62024TJ0357

JUDGMENT OF THE GENERAL COURT (Eighth Chamber, sitting with five Judges)

2 September 2026 ( *1 )

(Digital services – Regulation (EU) 2022/1925 – Designation of gatekeepers – Web browser – Article 3(2) and (5) of Regulation 2022/1925 – Important gateway for business users to reach end users – Presumption – Article 17(3) of Regulation 2022/1925 – Market investigation for designating gatekeepers – Action for annulment – Individual concern – Admissibility – Duty to state reasons – Error of law – Error of assessment – Principle of good administration)

In Case T‑357/24, Opera Norway AS , established in Oslo (Norway), represented by M. English, S. Terzulli Galí and L. Tristante Pellicer, lawyers, applicant, v European Commission , represented by M. Mataija, I. Naglis and I. Rogalski, acting as Agents, defendant, supported by Microsoft Corp ., established in Redmond, Washington (United States), represented by L. Kjølbye, J. Wileur, L. Bitsakou, T. Milleville and A. Aubry, lawyers, intervener, THE GENERAL COURT (Eighth Chamber, sitting with five Judges), composed, at the time of the deliberations, of M. van der Woude, President, G. De Baere, D. Petrlík (Rapporteur), K. Kecsmár and S. Kingston, Judges, Registrar: S. Spyropoulos, Administrator, having regard to the written part of the procedure, in particular:

– the plea of inadmissibility raised by the Commission by separate document lodged at the Registry of the General Court on 1 October 2024, – the decision of 14 January 2025 reserving the decision on the plea of inadmissibility;

– the written questions put by the Court to the parties, and their answers which were lodged at the Court Registry on 25 September 2025, further to the hearing on 22 October 2025, gives the following

Judgment

1By its action based on Article 263 TFEU, the applicant, Opera Norway AS, seeks annulment in part of Council Implementing Decision C(2024) 806 final of 12 February 2024 closing the market investigation opened by Decision C(2023)6078, pursuant to Article 17 of Regulation (EU) 2022/1925 of the European Parliament and of the Council on contestable and fair markets in the digital sector (Cases DMA.100015 Microsoft – online search engines, DMA.100028 Microsoft – web browsers and DMA.100034 Microsoft – online advertising services) (‘the contested decision’).

Background to the dispute

2The applicant is a software company operating, inter alia, the web browser Opera (‘Opera’).

3Microsoft Corp. (‘the intervener’ or ‘Microsoft’) is a company active in the technology sector.

4On 3 July 2023, Microsoft notified the European Commission, in accordance with the first subparagraph of Article 3(3) of Regulation (EU) 2022/1925 of the European Parliament and of the Council of 14 September 2022 on contestable and fair markets in the digital sector and amending Directives (EU) 2019/1937 and (EU) 2020/1828 (Digital Markets Act) ( OJ 2022 L 265, p. 1 ; ‘the DMA’), that it met the thresholds laid down in Article 3(2) of the DMA as regards, inter alia, the following core platform services (‘CPSs’):

– the Windows PC operating system (‘Windows PC OS’), – the online search engine Bing (‘Bing’), – the web browser Edge (‘Edge’), – the online advertising service Microsoft Advertising (‘Microsoft Advertising’).

5In the context of the notification referred to in paragraph 4 above, Microsoft submitted arguments, in accordance with Article 3(5) of the DMA, in order to maintain, inter alia, that, although Bing, Edge and Microsoft Advertising had met the quantitative thresholds laid down in Article 3(2) of the DMA, those services did not satisfy the requirements listed in Article 3(1) of the DMA because of the circumstances in which they operated, with the result that it should not be designated as a gatekeeper in respect of those services.

6On 5 September 2023, by Decision C(2023) 6106 final, the Commission, inter alia, designated Microsoft as a gatekeeper within the meaning of Article 3 of the DMA in respect of Windows PC OS.

7On the same day, by Decision C(2023) 6078 final, the Commission concluded that Bing, Edge and Microsoft Advertising were CPSs, but that Microsoft had put forward sufficiently substantiated arguments manifestly calling into question the presumptions laid down in Article 3(2) of the DMA in respect of each of those CPSs. Thus, the Commission opened a market investigation pursuant to Article 16(1) and Article 17(3) of the DMA (‘the market investigation’) in order to assess whether Bing, Edge and Microsoft Advertising should be listed as CPSs that constituted an important gateway for business users to reach end users, within the meaning of Article 3(1)(b) of the DMA (‘important gateway’).

8On 12 February 2024, the Commission adopted the contested decision.

9Under Article 1 of the contested decision, Microsoft is not designated as a gatekeeper, pursuant to Article 3(4) of the DMA, in relation to Bing, Edge and Microsoft Advertising.

Contested decision

10In the light of Microsoft’s arguments and the market investigation, the Commission reached the conclusion that, although Microsoft had met all the thresholds set out in Article 3(2) of the DMA, it had put forward sufficiently substantiated arguments to demonstrate that it did not meet the requirements set out in Article 3(1)(b) of the DMA as regards Edge. In that connection, the Commission relied in particular on the following three reasons.

11In the first place, the Commission found, in recitals 51, 53 to 55 and 57 of the contested decision, that the scale of usage of Edge in the web browser CPS category was low.

12In that regard, first, it is apparent from the information made available to the Commission during the market investigation that, in December 2022, Edge accounted for only 5.8% of web page views across all types of devices in the region ‘Europe’. Between 2020 and 2022, that figure was 3.9%. Those data show Edge’s lack of importance as a web browser in the European Union and, therefore, its lack of importance as a gateway for business users to reach end users.

13Second, according to the data submitted by Microsoft, the low scale of usage of Edge in the web browser CPS category is further confirmed when compared to other rival web browsers. In December 2022, Alphabet Inc.’s browser Chrome (‘Chrome’) represented 59% of web page views across all types of devices in the region ‘Europe’, and Apple Inc.’s browser Safari (‘Safari’) accounted for 22% of those views. Between 2020 and 2022, those figures were 60% and 20%, respectively, and 6.4% for another competitor, the browser Firefox (‘Firefox’). The other sources of data provided by the participants in the market investigation support those data.

14Third, the evidence available does not show that, at the time the contested decision was adopted, the integration of certain other Microsoft services into Edge resulted in a significant and sustained increase in Edge’s scale of usage.

15In the second place, as the Commission explains in recital 59 of the contested decision, Microsoft does not control Edge’s architecture because that architecture is dependent on the web browser engine Blink (‘the browser engine Blink’ or ‘Blink’). Browser engines play a critical role within a web browser in determining how content is loaded and displayed on a web page to end users. Consequently, the way in which content is rendered on Edge by business users to end users is predicated on conforming with Blink, rather than an autonomous choice by Microsoft as a web browser developer and operating system provider.

16In the third place, as is apparent from recitals 60 to 68 of the contested decision, Microsoft’s platform ecosystem (‘the ecosystem’) does not currently sufficiently contribute to making Edge an important gateway.

17It is true that Microsoft sought, for many years, to rely on its ecosystem to drive up the use of Edge, in particular by pre-installing it on its operating system Windows (‘Windows’), including Windows PC OS. Microsoft also offered incentives to original equipment manufacturers to set Edge as the default browser, pinned it as default web browser to the Windows taskbar and configured Windows PC OS and some of its other applications to open websites in Edge. When end users tried to download a rival web browser from Edge, a message was displayed to encourage them to abandon that step. Microsoft also gave preferential access to its chatbot ‘Bing Chat’ to Edge end users.

18However, the fact that Edge belongs to Microsoft’s ecosystem and the practices described in paragraph 17 above are not sufficient to establish that it currently constitutes an important gateway.

19First, Edge’s scale of usage remains relatively low. Despite the fact that Edge is pre-installed and set as the default on devices using Windows, Chrome’s scale of usage on those devices is significantly higher than that of Edge, while Edge’s scale of usage on those devices is only slightly higher than that of Firefox.

20Second, Microsoft’s ability to use Edge as a lever to drive up usage of other Microsoft products is currently limited and insufficient to consider Edge an important gateway. The low scale of usage of Bing as an online search engine in the European Union reflects Edge’s limited relevance in that respect.

21Third, and in any event, following its designation as a gatekeeper for Windows PC OS, Microsoft is obliged, under Article 6(3) of the DMA, to allow end users easily to uninstall any software application and easily to change default settings on that operating system.

22Fourth, although the majority of Edge’s competitors regard it as an important gateway, in particular because of its role within Microsoft’s ecosystem and its pre-installation and default setting, the responses from business users and other industry participants indicate that it does not constitute such a gateway. Less than one third of business users and other participants in the market investigation are of the opinion that it is ‘important’ or ‘crucial’, one quarter view it as ‘relevant’ and one third as ‘less relevant’ or ‘not relevant’. Only a very small number of business users and other participants in the market investigation consider that they cannot reach end users through web browsers other than Edge. In addition, website owners consider Chrome to be the most important web browser, followed by Safari, then by Edge and Firefox, which are ranked at a similar level. Only a very small number of website owners consider Edge to be the most, or second most, important web browser.

23In those circumstances, the Commission concluded, in recital 70 of the contested decision, that Edge was not an important gateway and decided, in Article 1 of the contested decision, that Microsoft should not be designated as a gatekeeper in relation to Edge.

Forms of order sought

24The applicant claims, in essence, that the Court should:

– annul the contested decision in so far as it finds that Microsoft should not be designated as a gatekeeper in relation to Edge;

– order the Commission to pay the costs.

25The Commission, supported by the intervener, contends that the Court should:

– dismiss the action as inadmissible or, in any event, as unfounded;

– order the applicant to pay the costs.

Law

Admissibility of the action

26The Commission, supported by the intervener, submits that the contested decision is not of individual concern to the applicant within the meaning of the fourth paragraph of Article 263 TFEU. In that regard, it follows from the case-law that a third party wishing to challenge an administrative decision taken in respect of another person must demonstrate, first, that it actively participated in the procedure leading up to the adoption of that decision and, second, that there are other specific circumstances, such as the manner in which its position on the market in question is affected by that decision, which demonstrate that that decision is of individual concern to it.

27In the first place, first of all, so far as concerns participation in the market investigation, the applicant was a reluctant participant. More specifically, on 20 September 2023, the Commission sent a standardised request for information to Edge’s competitors, including the applicant (‘the request for information sent to competitors’). At first, the applicant refused to reply to that request; it subsequently provided incomplete replies, at a late stage and only after several reminders from the Commission.

28In addition, the Commission submits that the rationale behind the case-law according to which third parties who have actively participated in an administrative procedure are entitled to challenge the decision taken at the end of that procedure is to ensure that the arguments put forward by those parties, but which were rejected by the administrative authority, may be reviewed by the Courts of the European Union. In the present case, in its reply to the request for information sent to competitors, the applicant did not consider that Edge was an important gateway, contrary to what it claims – for the first time – in its action for annulment.

29Lastly, according to the Commission, the applicant cannot claim that the DMA confers only very limited third-party rights in the context of an administrative procedure, with the result that its participation could not have gone beyond responding to the request for information sent to competitors. First, the applicant’s participation is much less involved than that of other competitors of Edge, which proactively submitted additional observations to the Commission. Second, the Commission published a press release, on 6 September 2023, to announce the opening of the market investigation. The applicant was therefore informed of that investigation before the request for information was sent to competitors and could have taken the initiative to engage in that investigation in addition to responding to that request, which it did not do.

30In the second place, as for the other specific circumstances which the applicant is required to demonstrate in order to be individually concerned by the contested decision, its status as an alternative provider of a web browser is merely an objective status which does not differentiate it from any other actual or potential provider of web browsers. In that regard, the applicant has not established any difference between it and other providers of such browsers.

31The applicant disputes those arguments.

32In accordance with the fourth paragraph of Article 263 TFEU, a natural or legal person may institute proceedings against a decision addressed to another person only if that decision is of direct and individual concern to the person seeking to bring proceedings.

33Persons other than those to whom a decision is addressed may claim to be individually concerned only if that decision affects them by virtue of certain attributes which are peculiar to them or by reason of circumstances in which they are differentiated from all other persons and thus distinguishes them individually just as in the case of the person to whom the decision is addressed (judgments of 15 July 1963, Plaumann v Commission, 25/62 , EU:C:1963:17 , p. 107 ; of 15 July 2021, Deutsche Lufthansa v Commission, C‑453/19 P , EU:C:2021:608 , paragraph 33 ; and of 26 June 2025, enercity v Commission, C‑485/23 P , EU:C:2025:483 , paragraph 31 ).

34In the situation of a decision by which the Commission decides not to designate an undertaking as a gatekeeper within the meaning of Article 3(1) of the DMA, whether a third party has such a specific status, and accordingly is individually concerned by that decision, within the meaning of the fourth paragraph of Article 263 TFEU, must be determined on the basis of a body of consistent evidence or on facts which may relate both to that undertaking’s participation in the administrative procedure and to the effect on its market position (see, to that effect and by analogy, judgments of 26 June 2025, enercity v Commission, C‑485/23 P , EU:C:2025:483 , paragraph 32 , and of 15 September 2016, Morningstar v Commission, T‑76/14 , EU:T:2016:481 , paragraphs 34 and 35 ).

35In the first place, first of all, as regards the effect on market position, the extent to which the applicant’s position on the market is liable to be affected by the lack of designation of an undertaking as a gatekeeper must, in particular, be assessed, since a substantial adverse effect on that position is a particularly relevant element in the body of evidence referred to in paragraph 34 above (see, to that effect and by analogy, judgment of 15 July 2021, Deutsche Lufthansa v Commission, C‑453/19 P , EU:C:2021:608 , paragraph 59 and the case-law cited).

36Demonstration by the applicant of a substantial effect on its market position does not entail a definitive ruling on the competitive relationship between that party and the undertaking which has not been designated as a gatekeeper, but requires only that that party adduce pertinent reasons to show that the decision in question may harm its legitimate interests by substantially affecting its position on the market (see, to that effect and by analogy, judgment of 15 July 2021, Deutsche Lufthansa v Commission, C‑453/19 P , EU:C:2021:608 , paragraph 57 and the case-law cited).

37Thus, the substantial adverse effect on the applicant’s market position results not from a detailed analysis of the various competitive relationships on that market, allowing the extent of the adverse effect on its market position to be established specifically, but, in principle, from a prima facie finding that the lack of designation of an undertaking as a gatekeeper leads to a substantial adverse effect on that position (see, to that effect and by analogy, judgment of 15 July 2021, Deutsche Lufthansa v Commission, C‑453/19 P , EU:C:2021:608 , paragraph 58 and the case-law cited).

38Such an adverse effect can in particular consist in the loss of an opportunity to make a profit or in less favourable developments than would have been the case had the undertaking which was not considered to be a gatekeeper been designated as such (see, to that effect and by analogy, judgment of 15 July 2021, Deutsche Lufthansa v Commission, C‑453/19 P , EU:C:2021:608 , paragraph 61 ).

39By contrast, the mere fact that an act such as the contested decision may exercise an influence on the competitive relationships existing on the market and that the applicant was in a competitive relationship with the undertaking which was not designated as a gatekeeper cannot suffice for that applicant to be regarded as individually concerned by that act (see, to that effect and by analogy, judgment of 26 June 2025, enercity v Commission, C‑485/23 P , EU:C:2025:483 , paragraph 82 ).

40Next, it should be noted that, under the second subparagraph of Article 6(3) of the DMA, the gatekeeper is required to allow and technically enable end users easily to change default settings on the operating system and web browser of the gatekeeper that direct or steer end users to products or services provided by the gatekeeper. That includes the obligation for the gatekeeper to, inter alia, prompt end users, at the moment of the end users’ first use of the gatekeeper’s web browser listed in the designation decision, to choose, from a list of the main available service providers, the web browser to which the operating system of the gatekeeper directs or steers users by default (‘the browser choice screen’). Pursuant to Article 3(10) of the DMA, the time limit within which to comply with that obligation is six months after a CPS has been listed in the designation decision.

41In that regard, the applicant and Microsoft stated, in essence, in their written pleadings, without being contradicted by the Commission on that point, that had Microsoft been designated as a gatekeeper in relation to Edge – and given that it had been designated as such in relation to Windows PC OS – it would have been required to present to end users of that web browser, upon their first use of Edge on Windows PC OS, the browser choice screen listing the main available web browser providers within the meaning of the second subparagraph of Article 6(3) of the DMA, among which those users could have chosen another default web browser.

42As regards the question whether the applicant’s web browser, namely Opera, would have been listed among such browsers, it should be noted that the applicant produced, in Annex A.4.13 to the application, data from the tool StatCounter (‘StatCounter’), from which it is apparent that, between June 2023 and June 2024, in the region ‘Europe’, that web browser was the fifth most significant browser on personal computers and the sixth on all devices in terms of share of total number of web page views. In addition, it is apparent from the data from StatCounter relating to personal computers for the period from January 2023 to March 2025, as reproduced in paragraph 44 of the statement in intervention, that Opera held the fifth position as regards those devices throughout that period.

43In that connection, neither the Commission nor Microsoft calls into question the reliability of those data or the fact that they relate to the region defined as ‘Europe’. On the contrary, those parties themselves rely on those data and acknowledge their relevance in the EU context, as is apparent, in particular, from recitals 43, 44 and 53 of the contested decision.

44In addition, in paragraph 10 of the statement in intervention, Microsoft referred to Opera, alongside Firefox, as an example of a ‘material web browser’. Similarly, in paragraph 58 of that statement, Microsoft expressly classified Opera, together with Chrome and Firefox only, among the ‘most popular Windows-compatible web browsers’.

45Moreover, Microsoft’s line of argument in paragraphs 10 and 58 of the statement in intervention seeks to demonstrate that its obligation, following its potential designation as a gatekeeper in relation to Edge, to present a browser choice screen would benefit primarily the online search engine Google Search, given that ‘all material web browsers other than Edge have Google Search set as the default search engine[, so that] if a user chose, e.g., Opera …, all searches made in [that web browser] would show results from Google Search’. By that line of argument, Microsoft thus acknowledged that if Edge were designated as an important gateway, Opera may have appeared on that browser choice screen.

46Moreover, neither the Commission nor Microsoft has submitted any evidence to show that the browser choice screen might contain a list of providers that was so limited that Opera would not be included on it, despite the undisputed information concerning its relevance, referred to in paragraphs 42 and 44 above.

47Lastly, the possibility raised by the Commission at the hearing that Opera’s importance could shrink in future has no bearing on the question whether that web browser would have appeared on the browser choice screen that Microsoft would have had to present following its potential designation as a gatekeeper in relation to Edge upon completion of the market investigation conducted with a view to adopting the contested decision.

48In those circumstances, the Commission cannot dispute the fact that, at the time the contested decision was adopted and, at the very least, within the six-month period which followed, the applicant was one of the main providers of web browsers in the European Union for the purposes of the second subparagraph of Article 6(3) of the DMA. Consequently, Opera may be regarded as a browser which would have appeared on the browser choice screen that Microsoft would have had to present to its users in the European Union had it been designated, on completion of the market investigation conducted with a view to adopting the contested decision, as a gatekeeper in relation to Edge.

49That conclusion is supported by the fact that, as is apparent from the documents, screenshots and extracts from web pages produced in Annexes A.4.6 to A.4.10 to the application, following the designation of Alphabet and Apple as gatekeepers in respect of Chrome and Safari, respectively, Opera appeared – in March and May 2024 – on Chrome and Safari’s browser choice screens, in all the Member States of the European Union.

50That being the case, the effects on the applicant’s position on the market linked to a browser choice screen that includes Opera not being displayed where Edge is used for the first time must be examined.

51In that regard, it should be noted that, according to the data from StatCounter submitted by Microsoft, on which the Commission relied in recital 53 of the contested decision, Edge represented, in December 2022, 5.8% of the web page views on all types of devices in the region ‘Europe’.

52In addition, it follows from recital 44 of the contested decision that, according to those data, the scale of usage of Edge in terms of number of web page views was, in December 2022, only slightly greater than Opera’s and therefore similar to that of Opera.

53It follows that the contested decision prevented the applicant from reaching more easily users of a rival web browser, Edge, the scale of usage of which was, at the time that decision was adopted, comparable to that of the applicant’s web browser, Opera. Although it is true that only some of Edge’s users would replace their web browser with Opera if they were offered the option of choosing another browser, the fact remains that making such an option available would have enabled the applicant to reach Edge’s end users in an effective manner and to increase its ability to compete with its operator, namely, Microsoft.

54That is all the more so since Opera – as the applicant highlights without being contradicted by the Commission or Microsoft – is specifically optimised for Windows PC OS, which is an operating system for personal computers. Edge’s scale of usage in the European Union on personal computers equipped with Windows PC OS represented between 20% and 30% of all browser minutes in the period from September 2022 to August 2023, as is apparent from the data provided by Microsoft and reproduced in footnote 50 to recital 53 of the contested decision. Consequently, a designation of Microsoft as a gatekeeper in relation to Edge would have had the potential to increase substantially Opera’s scale of usage.

55In those circumstances, it must be concluded that the applicant has submitted evidence demonstrating that the non-designation of Microsoft as a gatekeeper in relation to Edge was liable to have a substantial adverse effect on its market position, causing less favourable developments than would have been the case had the contested decision designated Microsoft as such.

56In the second place, as regards the applicant’s participation in the administrative procedure which preceded the adoption of the contested decision, it should be noted that the applicant was one of a limited number of Microsoft’s competitors which the Commission had itself chosen to invite to participate in that procedure by sending them a request for information. The applicant complied with that request by sending a reply on 12 October 2023.

57It is true that the mere reply to a request for information cannot be regarded, as such, as sufficient to distinguish the applicant individually for the purposes of the fourth paragraph of Article 263 TFEU (see, to that effect, judgment of 26 June 2025, enercity v Commission, C‑485/23 P , EU:C:2025:483 , paragraphs 38 and 43 ).

58Similarly, as the Commission maintains, the applicant’s replies to the request for information sent to competitors were very succinct and contained limited information, even though it had been expressly invited to express a view on whether Edge was an important gateway.

59However, the degree of the applicant’s participation in the administrative procedure must be assessed taking into account the specific features of the regulatory framework for the designation of gatekeepers established by the DMA, and in particular the fact that that regulatory framework does not provide for the participation of third parties in the administrative procedure, unless the Commission decides to send them a request for information under Article 21 of the DMA or to interview them on the basis of Article 22 of the DMA.

60In that context, account must also be taken of the fact that the applicant replied to the request for information sent to competitors despite that request not being a decision requesting information under Article 21(3) of the DMA, which undertakings must comply with, failing which the fine provided for in Article 30(3)(f) of the DMA may be imposed; it was merely a request for information under Article 21(2) of the DMA.

61Furthermore, the request for information sent to competitors was the only formal opportunity given by the Commission to enable Microsoft’s competitors to participate in the market investigation, with the result that the Commission cannot criticise the applicant, as it does by way of its argument set out in paragraph 29 above, for not having spontaneously sent it other observations.

62Thus, in the light of the specific features of the regulatory framework established by the DMA for the designation of gatekeepers, the applicant’s participation in the market investigation, albeit limited, must be taken into account as an additional element forming part of the body of evidence when examining its individual concern within the meaning of the fourth paragraph of Article 263 TFEU.

63Therefore, in view of the fact that the non-designation of Microsoft as a gatekeeper in relation to Edge was liable to have a substantial adverse effect on the applicant’s position on the market and, in addition, on the applicant’s participation in the administrative procedure which preceded the adoption of the contested decision, it must be held that it is individually concerned by the contested decision.

64Consequently, the plea of inadmissibility raised by the Commission must be rejected.

65As regards the condition, which has not been relied on in the plea of inadmissibility, that a natural or legal person must be directly concerned by the decision against which the action is brought, as recalled in paragraph 32 above, that condition requires two cumulative criteria to be met, namely, first, the contested measure must directly affect the legal situation of the individual and, second, it must leave no discretion to its addressees who are entrusted with the task of implementing it, such implementation being purely automatic and resulting from EU rules alone without the application of other intermediate rules (see judgment of 6 November 2018, Scuola Elementare Maria Montessori v Commission, Commission v Scuola Elementare Maria Montessori and Commission v Ferracci, C‑622/16 P to C‑624/16 P , EU:C:2018:873 , paragraph 42 and the case-law cited).

66In the present case, the non-designation Microsoft as a gatekeeper in relation to Edge prevented the applicant, as a provider of a rival web browser, from benefiting from the obligations imposed by the DMA on gatekeepers, in particular those relating to prompting a browser choice screen, with the result that the contested decision directly affects its legal situation. Moreover, that decision produces its legal effects purely automatically as a result of EU rules alone and without the application of other intermediate rules.

67It follows that the applicant is directly concerned by the contested decision.

68Since the applicant is directly and individually concerned by the contested decision, it must be concluded that it has standing to bring proceedings and that the action is admissible in that regard.

Substance

69The applicant relies on a single plea in law, alleging infringement of Article 3(1), (4) and (5) of the DMA, in that the Commission did not designate Microsoft as a gatekeeper in relation to Edge, based on the finding that that web browser was not an important gateway.

70That plea is divided into four parts.

71It should be noted, as a preliminary point, that, as is apparent from paragraphs 11 to 22 above, the contested decision is based on several grounds which led the Commission, in the context of an overall assessment, to take the view that, although Microsoft had met all the thresholds laid down in Article 3(2) of the DMA, it had put forward sufficiently substantiated arguments to demonstrate that it did not satisfy the requirements set out in Article 3(1)(b) of the DMA as regards Edge.

72Thus, the Commission relied in particular on (i) the low scale of usage of Edge in the web browser CPS category, (ii) Microsoft’s lack of control over Edge’s relevant architecture due to its dependence on the browser engine Blink, (iii) the finding that Microsoft’s ecosystem did not sufficiently contribute, at the date of the contested decision, to making Edge an important gateway, and (iv) on the fact that the responses of business users and other industry participants in the market investigation indicated that Edge was not an important gateway. In that latter respect, the Commission took account, in particular, of the fact that less than one third of the business users and other participants taking part in the market investigation had regarded Edge to be ‘important’ or ‘crucial’.

73By the first to third parts of the single plea in law, the applicant disputes the first three grounds referred to in paragraph 72 above. By the fourth part, it submits that those grounds were not sufficient to rebut the presumption laid down in Article 3(2)(b) of the DMA.

The first part of the single plea, alleging that the contested decision is incorrectly based on Edge’s market share

74The applicant submits that the contested decision is wrongly based on Edge’s low ‘market share’, calculated by reference to the share of the total number of web page views, since such an element is not relevant for the purposes of rebutting the presumption laid down in Article 3(2)(b) of the DMA, pursuant to which Edge is an important gateway. First, it follows from recital 10 of the DMA that, for the purposes of designating a gatekeeper, it is not appropriate to carry out an individual assessment of the market positions of the undertakings concerned. Second, recital 23 of the DMA states that the Commission should take into account only those elements which directly relate to the quantitative criteria, and that any justification based on economic grounds seeking to enter into market definition should be discarded, as it is not relevant to the designation of a gatekeeper.

75However, the Commission did not take into account any of the elements directly related to the quantitative criteria laid down in Article 3(2) of the DMA, which, according to recital 23 of the DMA, are the only elements that it should have taken into consideration. Instead of those elements, the Commission relied on the market shares of Edge and some of its competitors by presenting them as indicators of their scale, which constitutes an attempt to circumvent the terms of recital 23 of the DMA.

76Furthermore, the fact that Chrome and Safari are also significant web browsers, and possibly more important gateways, does not in itself mean that Edge is not an important gateway. It is the scale of Edge in absolute terms – assessed on the basis of the number of users – and the significance of the problems that that web browser poses in terms of fairness and contestability that justify it being regarded as an important gateway.

77The Commission, supported by Microsoft, disputes that line of argument.

78In that regard, it should be noted that, in recitals 51 to 58 of the contested decision, the Commission relied on the low scale of usage of Edge to conclude that that web browser was not an important gateway, noting, inter alia, that it represented, in December 2022, only 5.8% of web page views across all types of devices in the region ‘Europe’ and that that scale of usage was much lower than that of Chrome and Safari, which represented 59% and 22% of web page views, respectively (see paragraphs 11 to 13 above).

79In order to examine whether the Commission could take such elements into account to rebut the presumption laid down in Article 3(2)(b) of the DMA, in the first place, it must be recalled that, under the first subparagraph of Article 3(5) of the DMA, the undertaking providing CPSs may present, with its notification under the first subparagraph of Article 3(3) of the DMA, sufficiently substantiated arguments to demonstrate that, exceptionally, although it meets all the thresholds laid down in Article 3(2) of the DMA, due to the circumstances in which the relevant CPS operates, it does not satisfy the requirements listed in Article 3(1) of the DMA.

80It follows from recital 23 of the DMA that the only categories of arguments or evidence which the EU legislature decided to exclude explicitly as irrelevant are those deriving from a justification on economic grounds seeking to enter into market definition or to demonstrate efficiencies (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 46 ).

81It is also apparent from recital 23 of the DMA that, in order to be taken into consideration, the arguments and evidence submitted by the undertaking concerned must be ‘directly relate[d] to the quantitative criteria’, bearing in mind that the term ‘quantitative criteria’ refers to the quantitative thresholds laid down in Article 3(2) of the DMA (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 47 ).

82Such arguments and evidence are directly linked to those quantitative thresholds when they seek to rebut concretely and specifically one of the three presumptions laid down in Article 3(2) of the DMA (see, to that effect, judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 326 ).

83Recital 23 of the DMA expressly mentions, among the elements which directly relate to the quantitative criteria, the importance of the undertaking’s CPS considering ‘the overall scale of activities of the respective [CPS]’.

84In those circumstances, it is open to the Commission to take account of the low scale of usage of a CPS, which reflects its limited importance, in support of a finding that that CPS does not constitute an important gateway.

85Similarly, the Commission may compare the scale of usage of such a CPS with that of other CPSs. In that regard, first of all, it should be borne in mind that, as the Court has already held in its judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 , paragraphs 49 and 50 ), the list of elements that may be taken into account, referred to in recital 23 of the DMA, is not exhaustive.

86Next, an argument based on a comparison of the scale of usage of the CPSs concerned seeks to rebut concretely and specifically the presumption laid down in Article 3(2)(b) of the DMA. Such an argument demonstrates that, although it exceeds the user number thresholds laid down in that provision, the CPS concerned is of limited importance as a gateway compared to other web browsers.

87Lastly, the comparison of the scale of usage of the CPSs concerned forms part of the overall assessment of the ‘importance of the [CPS of the undertaking concerned]’, which recital 23 of the DMA expressly authorises the Commission to carry out.

88In the second place, contrary to what the applicant claims, comparing Edge’s scale of usage with that of other web browsers, on the basis of the share of the total number of web page views, does not mean that the Commission defined the market and that the scale of usage of Edge thus determined corresponds to a share of that market.

89In that regard, it should be noted that such an analysis presupposes that the Commission first defines the relevant market on which such a market share is held by the undertaking concerned.

90The definition of the relevant market involves determining the product market and the geographical market (see judgment of 27 June 2024, Commission v Servier and Others, C‑176/19 P , EU:C:2024:549 , paragraph 382 and the case-law cited).

91First, as regards the product market, the concept of ‘relevant market’ implies that there can be effective competition between the products or services which form part of it and this presupposes that there is a sufficient degree of interchangeability between all the products or services forming part of the same market in so far as a specific use of such products or services is concerned (see judgment of 27 June 2024, Commission v Servier and Others, C‑176/19 P , EU:C:2024:549 , paragraph 383 and the case-law cited). Second, as regards the relevant geographical market, its definition requires the determination of the territory in which all traders operate under the same conditions of competition in so far as concerns specifically the relevant goods or services (see judgment of 1 July 2008, MOTOE, C‑49/07 , EU:C:2008:376 , paragraph 34 and the case-law cited; judgment of 15 December 2016, DEI v Commission, T‑169/08 RENV , EU:T:2016:733 , paragraph 62 ).

92It is not apparent from the contested decision that the Commission carried out such assessments, whether in relation to the relevant product market or to the relevant geographical market.

93In that connection, the mere fact that the Commission took into account, in recitals 53 and 54 of the contested decision, the ‘share’ of the total number of web page views using Edge and rival browsers across all types of devices and on some of those types of devices, for the region ‘Europe’, does not mean that it defined a specific market for web browsers according to the principles recalled in paragraphs 89 to 91 above. In particular, the Commission did not express any view on whether it was appropriate to define relevant markets according to the type of device or for a particular region.

94Similarly, the applicant cannot rely on the fact that, in footnote 48 to recital 53 of the contested decision, the Commission stated that ‘Microsoft [had] provided StatCounter data on web browser market share in Europe, disaggregated across different device types’. The reference to ‘market share’, called into question by the applicant, corresponds to the way in which those data are designated by StatCounter, as is apparent from Annex A.4.13 to the application. By contrast, it does not follow from that footnote that the Commission defined the market according to the principles recalled in paragraphs 89 to 91 above.

95In the third place, the other complaints raised by the applicant in support of the present part of the plea must be rejected.

96First, the applicant cannot rely on recital 10 of the DMA to criticise the Commission for having taken into account, in the contested decision, the share of the total number of web page views using Edge. In that recital, the EU legislature merely takes a position on the relationship between the DMA, Articles 101 and 102 TFEU, certain national competition rules and national rules on merger control, without deciding the elements which the Commission may take into account in its assessment of the arguments and evidence submitted to rebut the presumptions laid down in Article 3(2) of the DMA.

97Second, the applicant cannot rely on the finding in recital 146 of Commission Decision C(2023) 6102 final of 5 September 2023 designating ByteDance as a gatekeeper pursuant to Article 3 of [the DMA] (DMA.100040 ByteDance – Online social networking services), according to which the mere fact of being smaller in size than other providers of CPSs is insufficient on its own to rebut the presumptions laid down in Article 3(2) of the DMA. First, the Commission is required to carry out an individual appraisal of the circumstances of each case, without being bound by previous decisions concerning other undertakings or other CPSs (see, to that effect, judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 68 ). Second, that finding is, in any event, in no way incompatible with the finding referred to in the contested decision, by which the Commission did not confine itself to taking into account the scale of usage of Edge compared with that of some of its competitors, but also relied on other circumstances when examining the rebuttal of the presumption laid down in Article 3(2)(b) of the DMA (see paragraphs 11 to 22 above).

98Third, it is also necessary to reject the applicant’s argument that, in essence, even if it were open to the Commission to take account of the share of the total number of web page views, such a criterion is not sufficient to assess the importance of a web browser by reference to the overall scale of its activities and the Commission should have assessed that importance above all in the light of the very high number of its users, which is an essential criterion.

99In that regard, it should be noted that, as is apparent from recital 56 of the contested decision, the Commission took into account the fact that the number of end users of Edge was high. However, it concluded, in the same recital, that ‘irrespective of the high number of end users, Edge’s scale of usage compared to other web browsers [was] significantly lower’. It follows that, according to the Commission’s assessment, the relevance of the high number of end users of Edge is outweighed by considerations based on its low scale of usage compared with other web browsers, in terms of number of web page views.

100There is nothing in Article 3(5) or recital 23 of the DMA to suggest that considerations relating to the number of end users are, as a matter of principle, predominant in comparison with other considerations which may be relevant in assessing the importance of a web browser by reference to the overall scale of its activities.

101Fourth, the applicant maintains that the Commission did not take sufficient account of the fact that a large number of users of personal computers equipped with Windows PC OS in the European Union used Edge repeatedly to access the internet. In so far as the use of personal computers represents a very significant share of internet use, the importance of those users cannot, according to the applicant, be disregarded or minimised by stating that they are only one ‘subset of the relevant end users’, as the Commission maintains. The latter should have assessed whether Edge was an important gateway for personal computer users, since they form a ‘certain categor[y] of users’, within the meaning of the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 178 ).

102In that connection, it must be borne in mind that Article 2(2)(g) of the DMA defines the CPS category to which Edge belongs, inter alia, as ‘web browsers’, without drawing a distinction according to the different types of devices or the operating systems on which those browsers are used. This is consistent with the objective expressed in recital 14 of the DMA, according to which the definition of CPSs should be technology neutral and should be understood as encompassing those provided on or through various means or devices.

103In addition, according to recital 23 of the DMA, the importance of the undertaking’s CPS should be assessed taking into account the ‘overall scale’ of its activities.

104Moreover, where the undertaking concerned presents arguments relating to the elements listed in recital 23 of the DMA, such as that referred to in paragraph 103 above, account must be taken, in accordance with Article 3(5) of the DMA, of the circumstances in which the relevant CPS operates (see, to that effect, judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 176 ).

105It follows that the importance of web browsers cannot be assessed exclusively by reference to a single group of devices or operating systems by which they are proposed.

106In those circumstances, the Commission was entitled to assess Edge’s importance by taking account of all the devices on which it was available and to conclude, as it did in recital 65 of the contested decision, that, in the light of the evidence available to it, Edge’s higher scale of usage on personal computers equipped with Windows PC OS was not a sufficient indicator that Edge was an important gateway.

107That conclusion is not called into question by the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 ).

108In that regard, it should be noted that, in the case which gave rise to the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 ), the undertaking concerned claimed that it should not be designated as a gatekeeper in respect of its online social network platform, on the ground that its end users were multi-homing, that is to say, they used, in addition to the platform concerned, one or more other platforms.

109The Court responded to that argument by finding that the mere fact that users of an online social networking platform used other online social networking platforms in parallel did not mean that those different platforms were of equal importance to them. Thus, the intensity of such a use, that is to say, the time spent by a user interacting on that platform, and the importance of such a platform for certain categories of users, may constitute, among other factors, and as the case may be, relevant factors for assessing whether the existence of a certain degree of multi-homing can manifestly call into question the presumption that the CPS concerned is an important gateway (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 178 ).

110Those considerations were made in the context of multi-homing, which is not at issue in the present case. Furthermore, it cannot be inferred from those considerations that a CPS must be regarded as an important gateway on the sole ground that it is of particular importance to reach a certain category of end users. As has been noted in paragraphs 103 and 104 above, pursuant to recital 23 and Article 3(5) of the DMA, account must be taken of the overall scale of the activities of the CPS concerned and of all the circumstances in which it operates.

111Fifth, the applicant submits that the Commission should have taken into account the fact that Edge is the most important gateway for suppliers of rival web browsers, which allows them, as business users of Edge, to reach Windows PC OS end users. Due to the pre-installation of Edge on computers equipped with that operating system, end users relied on that browser to download rival browsers, such as Opera, at least in respect of the first rival browser installed.

112In that regard, while it is true that Edge’s scale of usage on Windows PC OS was, as has been pointed out in paragraph 54 above, in the range of 20% to 30% and that the first download of a rival browser of Edge on Windows PC OS was always carried out through Edge, the fact remains that Chrome’s scale of usage on Windows PC OS was of 50% to 60%, and that of Firefox was of 10% to 20%, as is apparent from footnote 50 to recital 53 of the contested decision. Those data show that the providers of rival browsers were able to overcome the fact that the first download of a browser other than Edge on Windows PC OS was carried out through that latter browser.

113Sixth, the applicant submits that it is apparent from the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 239 ), that the Commission had to take account of the fact that Edge’s share of supply on personal computers had increased rapidly in Europe from 0% at the time of its launch in 2015 to approximately 14% in 2024.

114In that regard, Microsoft explained, without being contradicted by the applicant on that point, that it had launched Edge in 2015 as a replacement for its prior web browser, Internet Explorer, and that, over time, as end users replaced Internet Explorer with Edge, the latter browser had experienced a certain growth, but that that growth had occurred, to a very large extent, to the detriment of Internet Explorer. It follows that, as regards its web browsers, Microsoft has not experienced a rapid and significant growth in the total number of end users in the European Union, unlike the undertaking concerned in the case which gave rise to the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 ).

115Seventh, in its observations on Microsoft’s statement in intervention, the applicant complains that the Commission assessed Edge’s scale of usage solely on the basis of StatCounter’s data, which are imprecise.

116In that regard, it must be borne in mind that, in accordance with Article 84(1) of the Rules of Procedure of the General Court, no new plea in law or submission may be introduced in the course of proceedings unless it is based on matters of law or of fact which come to light in the course of the procedure (judgment of 14 December 2022, PT Pelita Agung Agrindustri and PT Permata Hijau Palm Oleo v Commission, T‑143/20 , EU:T:2022:811 , paragraph 149 ).

117Those principles also apply to submissions put forward for the first time in the observations on a statement in intervention (see, to that effect, judgment of 5 May 2021, ITD and Danske Fragtmænd v Commission, T‑561/18 , EU:T:2021:240 , paragraphs 183 to 185 ).

118The present complaint was not raised in the application, although it relates to the grounds set out in recital 55 of the contested decision. Furthermore, the applicant has not claimed that that complaint was based on matters of law or of fact which came to light in the course of the procedure. In those circumstances, that complaint, which does not constitute an amplification of a complaint previously put forward in the application, must be rejected as inadmissible.

119In any event, that complaint is unfounded. It is apparent from recital 55 of the contested decision that, following the observations of the participants in the market investigation, the Commission analysed Edge’s scale of usage by also taking into account data other than those stemming from StatCounter; those other data confirmed its analysis based on that tool. It is also apparent from Questions C.1 and C.2 of the request for information sent to competitors, which is in the Court’s file in Annex B.1.2 to the plea of inadmissibility raised by the Commission, that the Commission asked Microsoft’s competitors about the reliability of StatCounter’s data. However, in its reply to that request for information, the applicant did not criticise the reliability of StatCounter’s data.

120In the light of all of the foregoing, the first part of the single plea in law must be rejected.

The second part of the single plea, alleging that the contested decision is incorrectly based on Microsoft’s alleged lack of control of the relevant architecture of Edge

– Arguments of the parties

121The applicant maintains that the Commission wrongly based the contested decision on the fact that Microsoft did not control Edge’s relevant architecture, because Edge used Blink and not its own browser engine. The use of Blink over an engine of its own clearly cannot contribute meaningfully to rebutting the presumption that Edge was an important gateway. Furthermore, the contested decision does not contain an adequate statement of reasons in that regard.

122The Commission, supported by Microsoft, disputes that line of argument.

– Preliminary remarks

123It should be borne in mind that a browser engine is software which converts the code in which the content of a web page is written into a styled and interactive page displayed on the end user’s screen. That process involves applying the rules set out in the website code, so that its design and functionalities appear in the form the author of that website has planned.

124Web browsers use different browser engines. Edge, Opera and Chrome rely on Blink, a rendering engine which ensures, inter alia, the interpretation and display of the content written in the HTML and CSS codes. Blink is an open source software managed by Chromium. The latter is an open source software development project for undertakings offering a web browser.

125In order to create a complete web browser, undertakings develop additional software around the browser’s engine. That software governs, inter alia, user interface, the operation of the address bar and of the settings menus, the storage of passwords or the browser’s security policy.

– The statement of reasons for the contested decision as regards Blink

126The applicant submits that the contested decision is vitiated by a failure to state reasons as regards whether, and to what extent, the fact that Edge uses Blink – and not its own browser engine – is a relevant element in assessing whether Edge is an important gateway. That decision contains a single recital relating to that element and the explanations given by the Commission before the General Court do not appear in that decision.

127In accordance with the second paragraph of Article 296 TFEU, legal acts must state the reasons on which they are based. Similarly, the right to good administration, enshrined in Article 41 of the Charter of Fundamental Rights of the European Union, lays down the obligation for the EU institutions to give reasons for their decisions.

128The statement of reasons must disclose in a clear and unequivocal fashion the reasoning followed by the author of that act in such a way as to enable the persons concerned to ascertain the reasons for the act and to enable the competent court to exercise its power of review (judgment of 3 July 2025, Instituto Cervantes and Spain v Commission, C‑534/23 P and C‑539/23 P , EU:C:2025:523 , paragraph 122 ).

129Such a statement of reasons must be adapted to the nature of the act at issue and to the context in which it was adopted. In that regard, it is not necessary for the reasoning to go into all the relevant facts and points of law, since the question whether the statement of reasons is sufficient must be assessed with regard not only to its wording but also to its context and to all the legal rules governing the matter in question and, in particular, to the interest which the addressees of the act may have in obtaining explanations. Consequently, the reasons given for an act adversely affecting a person are sufficient if that act was adopted in a context which was known to that person and which enables him or her to understand the scope of the measure taken (see, to that effect, judgments of 15 July 2021, Commission v Landesbank Baden-Württemberg and SRB, C‑584/20 P and C‑621/20 P , EU:C:2021:601 , paragraph 104 and the case-law cited, and of 10 September 2024, Commission v Ireland and Others, C‑465/20 P , EU:C:2024:724 , paragraph 392 and the case-law cited).

130In the present case, recital 59 of the contested decision explained Blink’s relevance for the rebuttal of the presumption laid down in Article 3(2)(b) of the DMA; that recital reads as follows:

‘The Commission notes that Microsoft does not control the relevant [architecture of Edge], in particular because [the latter] does not have its own browser engine but is instead dependent on … [the browser engine Blink]. As pointed out by Microsoft [during the administrative procedure], browser engines perform a critical role within a web browser in determining how content is loaded and displayed on a webpage to end users. Consequently, the way in which content is rendered on Edge by business users to end users is predicated on conforming with the [engine Blink], rather than an autonomous choice by Microsoft as a web browser developer and operating system provider.’

131While it is true that the reasons referred to in paragraph 130 above are succinct, they must be read, in accordance with the principles recalled in paragraph 129 above, in the light of the following elements.

132First, according to recital 43 of the DMA, each web browser is built on a web browser engine, which is responsible for key browser functionality such as speed, reliability and web compatibility. When gatekeepers operate and impose web browser engines, they are in a position to determine the functionality and standards that will apply not only to their own web browsers, but also to rival web browsers and, in turn, to web software applications.

133Recital 43 of the DMA therefore highlights the importance of a browser engine for the operation of a web browser and thus makes it possible to understand that the use, by the provider of such a browser, of a third-party browser engine is likely to reduce that provider’s ability to set the speed, reliability and compatibility of its web browser, namely the latter’s main functionalities, which constitute, without it being contested, essential elements, inter alia, for business users.

134Second, in recital 47 of the contested decision, the Commission included a summary of the arguments put forward by Microsoft during the administrative procedure concerning the relevance of Edge’s use of Blink. According to that recital, Microsoft maintained, inter alia, that the main reason for using Blink was that business users did not ensure the operability of their websites with its browser engine and that software providers did not create extensions for that browser engine. The effect thereof was that some websites did not support Microsoft’s engine, which resulted in the suboptimal performance of those websites on Edge. Accordingly, end users switched to Chrome and Safari for a better browsing experience. Consequently, Microsoft was left with no alternative but to abandon its own browser engine and to use Blink. According to that recital, Microsoft maintained that it could not therefore influence the operations of business users to its advantage because those undertakings did not optimise their websites specifically for Edge.

135In that regard, recital 47 of the contested decision not only makes it possible to understand the reasons why Microsoft chose to use Blink in Edge, but it also contains reasons why Microsoft had little incentive to make changes to Blink.

136Admittedly, as the applicant maintains, recital 47 of the contested decision merely summarises the arguments put forward by Microsoft during the administrative procedure.

137However, recital 59 of the contested decision – which contains the Commission’s assessment – emphasises the need for Microsoft to ensure that Edge is compatible with Blink and refers to the information provided by Microsoft during the administrative procedure concerning the essential role of browser engines. In those circumstances, it is necessary to take into account the information contained in recital 47 of the contested decision in order to assess whether the statement of reasons for that decision is sufficient.

138Third, according to its own statements, the applicant is also one of the providers of web browsers which use Blink in their web browsers. Such providers are necessarily aware of Blink’s role in the design of web browsers and of the implications that a dependency on a third-party browser engine is likely to have in assessing whether a web browser is an important gateway.

139In the light of those elements, it must be held that the statement of reasons for the contested decision enables the applicant to assess the link between Microsoft’s use of Blink and the Commission’s conclusion that Edge is not an important gateway; it also enables the Court to conduct a review in that regard. Such a statement of reasons therefore satisfies the requirements set out in paragraph 128 above.

140That conclusion is not called into question by the arguments raised by the applicant in its reply to the measures of organisation of procedure of 9 September 2025, according to which recital 59 of the contested decision does not make it possible to understand how the Commission assessed certain specific elements, such as whether the choice of a browser engine was an element which relates directly to the quantitative criteria laid down in Article 3(2) of the DMA, what comprises a browser engine, the reasons why Microsoft decided to use Blink or the link between the low scale of usage of Edge and Microsoft’s decision to use Blink.

141In that regard, it is sufficient to recall that the Commission is not required to adopt a position on all the arguments relied on before it during the administrative procedure so long as it sets out the facts and the legal considerations which are of decisive importance in the context of its decision (judgment of 27 April 2023, Casa Regina Apostolorum della Pia Società delle Figlie di San Paolo v Commission, C‑492/21 P , not published, EU:C:2023:354 , paragraph 49 ; see also, to that effect, judgment of 1 July 2008, Chronopost and La Poste v UFEX and Others, C‑341/06 P and C‑342/06 P , EU:C:2008:375 , paragraph 96 ).

142This is all the more so in the case of arguments which were not raised before it, since the Commission is not required to anticipate potential objections in the reasoning for its decisions (see, to that effect, judgments of 25 October 2005, Germany and Denmark v Commission, C‑465/02 and C‑466/02 , EU:C:2005:636 , paragraph 106 , and of 27 April 2023, Casa Regina Apostolorum della Pia Società delle Figlie di San Paolo v Commission, C‑492/21 P , not published, EU:C:2023:354 , paragraph 49 and the case-law cited).

143In the present case, it must be held, for the reasons mentioned in paragraphs 130 to 139 above, that the Commission set out the main reasons why Edge’s use of Blink, and not of a Microsoft browser engine, contributed to the finding that Edge was not an important gateway.

144In addition, the request for information sent to competitors, which was also addressed to the applicant, contained seven questions on web browser engines, namely Questions E.1 to E.7. The applicant was therefore informed that the Commission was investigating the relevance of those browser engines. Despite that, the applicant did not rely on the elements referred to in paragraph 140 above either in response to those questions or in response to Question F.3, which invited the addressees of that request to inform the Commission of any other observations which might be useful for its examination.

145In those circumstances, the applicant cannot complain that the Commission did not adopt a position on those elements in the statement of reasons for the contested decision.

– Whether the complaint, claiming that the contested decision is incorrectly based on Microsoft’s alleged lack of control of the relevant architecture of Edge, is well founded

146In the first place, the applicant submits that there is nothing in the DMA to indicate that the importance of a web browser, as a gateway, depends on its provider’s ability to determine how the content is rendered on that browser. In addition, such an element does not directly relate to the quantitative thresholds laid down in Article 3(2) of the DMA, with the result that the Commission was unable to take it into consideration when examining the rebuttal of the presumption laid down in Article 3(2)(b) of the DMA.

147In that regard, it is apparent from the principles recalled in paragraphs 79 to 82 above that Article 3(5) of the DMA does not exclude from the outset, as irrelevant, certain types of arguments or evidence submitted by an undertaking for the purposes of rebutting the presumptions laid down in Article 3(2) of the DMA, with the exception of arguments or evidence deriving from a justification on economic grounds seeking to enter into market definition or to demonstrate efficiencies. The Commission may thus take account, in principle, of all the elements put forward which are intended to rebut concretely and specifically one of the three presumptions laid down in the latter provision.

148The use of a third-party browser engine is capable of rebutting concretely and specifically the presumption laid down in Article 3(2)(b) of the DMA, relating to the question whether a CPS is an important gateway.

149As stated in recital 20 of the DMA, the level of importance of a gateway depends, in particular, on the possibility for the undertaking providing a CPS to influence the operations of a substantial part of business users to its advantage. It follows from the considerations set out in paragraphs 123 to 125 above that it cannot be ruled out that the use of a third-party browser engine reduces, or even negates, the possibility for a provider of a web browser to change the parameters of that browser which would enable it to influence the operations of a substantial part of business users to its advantage. In particular, the use of a third-party browser engine may prevent such a provider from designing the web browser in question in such a way that certain websites cannot function properly with that browser or that other websites may function more rapidly or effectively on that browser. Consequently, such an element may be relevant for the purposes of rebutting the presumption that that browser is an important gateway.

150In that regard, the applicant cannot claim that the use of a third-party browser engine is a ‘purely qualitative’ element which cannot, under recital 23 of the DMA, be taken into account for the purposes of rebutting the presumption laid down in Article 3(2)(b) of the DMA.

151As has already been held, Article 3(5) of the DMA, read in the light of recital 23 thereof, must be interpreted as allowing the undertaking concerned to submit, in order to rebut the presumptions laid down in Article 3(2) of the DMA, arguments and evidence, whether or not they are expressed in figures, provided that they relate directly to one or more of those presumptions (see, to that effect, judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraphs 40 to 51 ).

152Furthermore, it is not claimed that the use of a third-party browser engine is an irrelevant argument in the light of the case-law referred to in paragraph 80 above, because it derives from a justification on economic grounds seeking to enter into market definition or demonstrate efficiencies.

153In those circumstances, the Commission was entitled to take into consideration the fact that a web browser was based on a third-party browser engine when examining the rebuttal of the presumption laid down in Article 3(2)(b) of the DMA.

154In the second place, the applicant claims that the Commission failed to take account of the fact that Blink was an open source code product, so that Microsoft was free to develop, modify, adapt or abandon that product.

155In that connection, it should be recalled that, in accordance with Article 1(1) of the DMA, the purpose of that regulation is to contribute to the proper functioning of the internal market by laying down harmonised rules ensuring for all businesses contestable and fair markets in the digital sector across the Union where gatekeepers are present, to the benefit of business users and end users.

156The objective of ensuring the contestability of markets in the digital sector relates, as is apparent from recital 32 of the DMA, to the ability of undertakings effectively to overcome barriers to entry and expansion and challenge the gatekeeper on the merits of their products and services. The objective of ensuring fairness of those markets, as is apparent from recital 33 of the DMA, is to prevent an imbalance between the rights and the obligations of business users where the gatekeeper obtains a disproportionate advantage, bearing in mind that, due to their gateway position and superior bargaining power, it is possible that such gatekeepers engage in behaviour that does not allow others to capture fully the benefits of their own contributions, and unilaterally set unbalanced conditions for the use of their CPSs or services provided together with, or in support of, their CPSs.

157In addition, it is noted in recital 20 of the DMA that the level of importance of a gateway depends, inter alia, on the possibility for the gatekeeper to influence the operations of a substantial part of business users to its advantage.

158In that regard, and so far as concerns specifically web browsers, it is apparent from recital 43 of the DMA that it is the browser engine which is responsible for key browser functionality such as speed, reliability and the compatibility of web pages with a web browser. In addition, that recital states that browser engines are crucial for business users because they enable them to conduct their business and allow them to optimise services.

159It is in that context that the Court must examine whether the Commission wrongly failed to take account of the fact that Blink was an open source product to which Microsoft could make modifications.

160In that connection, the applicant maintains that Microsoft could, in essence, make three types of modifications to Blink. First, Microsoft could have applied its own modifications to the Blink code before incorporating it into the Edge code. Second, it could have applied upstream modifications by contributing itself to the Chromium project. Third, it could have applied real-time manipulation to websites by modifying their code, for example by means of a built-in ad blocker in Edge.

161As regards the first and third types of modifications referred to in paragraph 160 above, first, it is not disputed that Microsoft abandoned its own browser engine on the ground that its use did not allow a product of sufficient quality to be offered to end users, the main reason being that website owners no longer ensured that their sites were compatible with Edge. Thus, Microsoft decided to use Blink to ensure that the content of websites was correctly rendered on Edge. Second, as is apparent from recitals 47 and 59 of the contested decision, Microsoft has no incentive to apply modifications to Blink which would affect the speed, the reliability of Edge or the compatibility of web pages with Edge, since such modifications would give rise to the same suboptimal performance of Edge which led it to replace its own browser engine with Blink.

162Furthermore, as regards the examples of modifications referred to by the applicant in its application to illustrate how Edge diverges from Blink, it is apparent from the clarifications provided by Microsoft in response to the measures of organisation of procedure of 9 September 2025, which have not been disputed by the applicant, that all of those modifications – with one exception – constitute changes which Microsoft made to the software referred to in paragraph 125 above, namely to the software developed around the browser engine to offer a complete web browser, and not to Blink itself. The applicant cannot therefore rely on such modifications in support of its argument that Microsoft made certain modifications to Blink.

163The only exception concerns the modification referred to in paragraph 56(a) of the application, which relates to an application programming interface known as ‘Storage Access’, by which, according to Microsoft’s explanations, Edge allows websites to seek end users’ consent regarding privacy, such as blocking third-party cookies.

164It is true that that software affects the manner in which business users can reach end users. However, the applicant has not sufficiently explained how the use of such software gave Microsoft the possibility of influencing to its advantage the operations of a substantial part of business users.

165As regards the second type of modifications referred to in paragraph 160 above, namely those which Microsoft could have made to Blink ‘upstream’ by contributing to the Chromium project, it is apparent from the applicant’s and Microsoft’s replies to the measures of organisation of procedure of 9 September 2025 that Microsoft can only propose such modifications – in the same way as any other person – and that they must, each time, be reviewed and approved by a Chromium administrator before being integrated into Blink. Such a possibility of influencing Blink does not therefore confer on Microsoft a sufficient degree of autonomy to call into question the Commission’s finding that Microsoft does not control the relevant architecture of Edge owing to the latter’s use of Blink.

166It follows from the foregoing that the applicant has not shown that the fact that Blink is an open source product to which Microsoft could make modifications was such as to invalidate the Commission’s finding that Edge’s use of that browser engine contributed to Edge not being regarded as an important gateway.

167In the third place, the applicant claims that Microsoft’s choice to use a third-party browser engine does not alter the fact that a very large number of business users depend on Edge – and on the way in which Microsoft configures that browser – in order to reach a very large number of end users. Thus, Microsoft can continue to influence, inter alia, the content of websites, the possibility for website providers to monetise their content and the possibility for third parties and competitors to track internet traffic.

168In that regard, first of all, it should be recalled that the number of end users is not the only relevant element for the purposes of rebutting the presumption laid down in Article 3(2)(b) of the DMA (see paragraph 147 above).

169Next, it has already been established in paragraphs 78 to 87, 99 and 100 above that the Commission could rightly take the view that the relevance of Edge’s high number of end users was outweighed by considerations based on its low scale of usage compared with other web browsers.

170In addition, as has been noted in paragraph 153 above, the Commission was entitled to, without making an error of assessment, take into consideration the use of Blink in order to rebut the presumption laid down in Article 3(2)(b) of the DMA. That use is thus an additional factor which further reduces the importance of Edge’s high number of end users. In those circumstances, the Commission was entitled to consider that the use of that browser engine was a relevant factor in support of the conclusion that Edge was not an important gateway.

171Lastly, and in any event, the applicant has not submitted to the Court any sufficiently substantiated evidence to show that Edge’s functionalities which were not part of the browser engine had a significant impact on business users.

172In those circumstances, the applicant’s arguments must be rejected.

173In the light of the foregoing, the second part of the single plea in law must be rejected.

The third part of the single plea, according to which the Commission erred in finding that Microsoft’s ecosystem did not sufficiently contribute to making Edge an important gateway

174The applicant maintains that the Commission was wrong to take the view that Microsoft’s ecosystem did not sufficiently contribute to making Edge an important gateway. The integration of Edge into that ecosystem and the practices implemented by Microsoft with the aim of increasing the scale of usage of that web browser are precisely the reasons why the thresholds laid down in Article 3(2) of the DMA were met.

175Edge’s scale of usage on personal computers is at least 65.5 times greater than its share on mobile devices. As regards solely personal computers equipped with Windows PC OS, the percentage of usage of Edge appears to be 115 to 165 times higher than on mobile devices. Those data confirm the artificial advantages enjoyed by Edge in relation to its competitors and the extent to which Microsoft’s practices and the advantages arising from its ecosystem benefit Edge, to the detriment of Microsoft’s users and competitors. Thus, having regard to the advantages which Microsoft’s ecosystem confers on Edge, the Commission should have concluded that Edge was an important gateway.

176The Commission, supported by Microsoft, disputes that line of argument.

177The DMA does not comprise a definition of the term ‘ecosystem’. Nevertheless, the meaning of that concept can be inferred from recitals 3, 32 and 64 of the DMA, from which it is apparent, in essence, that a digital platform ecosystem may consist of one or more CPSs and other services connected to them, for example by means of technological links or interoperability; this is liable to exacerbate entry barriers for competitors of those undertakings and increase the cost of switching providers for end users, making it more difficult for existing or new market operators to compete with those undertakings or contest their position (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 128 ).

178Consequently, a digital ‘ecosystem’ exists where several categories of suppliers, customers and consumers are brought together and interact within a platform, and where the products or services comprising that ecosystem may overlap with, or be connected to, each other in terms of their horizontal or vertical complementarity (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 129 ).

179It is apparent from recital 3 of the DMA that one of the characteristics of certain gatekeepers is precisely the fact that they exercise control over whole platform ecosystems in the digital economy (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 130 ).

180It follows that having a digital platform ecosystem can constitute a relevant factor for the purposes of assessing whether the undertaking concerned is a gatekeeper and whether, more particularly, the CPS at issue is an important gateway (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 131 ).

181In the present case, it is common ground between the main parties that Microsoft has an ecosystem of which Edge forms part, that that ecosystem is composed, inter alia, of Windows and that it enables Microsoft to promote the use of Edge, by pre-installing Edge on Windows, by incentivising original equipment manufacturers to set it as the default browser, by pinning it to the Windows task bar as the default web browser and by configuring Windows PC OS and some of its other software so that websites are opened by default in Edge. It is also common ground that the online search engine Bing is one of the components of Microsoft’s ecosystem.

182However, it should be noted that it is the benefits or disadvantages associated with the existence or absence of an ecosystem which are the elements that make it possible to assess whether the CPS concerned is an important gateway, and not the mere existence or absence of an ecosystem as such, since the very concept of ‘ecosystem’ encompasses various business models. Therefore, each ecosystem must be examined on a case-by-case basis, taking into account the benefits or lack of benefits deriving from such a business model, in particular as regards contestability (judgment of 17 July 2024, Bytedance v Commission, T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 134 ).

183In that latter regard, and contrary to what the applicant appears to claim, it is not apparent from either Article 3(8)(f) of the DMA or recitals 2, 11 and 13 thereof that it is the vertical integration of the undertaking concerned as such, and therefore its ecosystem as such, which should lead to the CPS concerned being regarded as an important gateway, irrespective of the effects of that integration on the market. Aside from the fact that the wording of that provision and of those recitals does not support such an argument put forward by the applicant, it follows from Article 3(5) of the DMA that the assessment which the Commission is required to carry out, where an undertaking submits arguments to rebut the presumptions laid down in Article 3(2) of the DMA, must take account of the circumstances in which the CPS concerned operates.

184It follows that the Commission was right to examine whether Edge’s integration into Microsoft’s ecosystem would necessarily lead to that web browser being regarded as an important gateway.

185In that regard, it is apparent from recitals 63 to 68 of the contested decision, the main points of which are set out in paragraphs 16 to 22 above, that notwithstanding the various practices implemented by Microsoft in order to increase the use of Edge, the Commission considered that the scale of usage of that web browser had remained low and that that of the rival browsers Chrome and Safari, respectively, was considerably higher. Similarly, the Commission observed that, because of its low scale of usage, Microsoft could not use Edge as a lever to drive up usage of the other components of its ecosystem, such as its online search engine Bing.

186None of the arguments put forward by the applicant calls into question the validity of those findings.

187First, the applicant submits that Microsoft’s vertical integration, its conglomerate corporate structure, its economies of scale and scope and the advantages they confer on Edge are not reasons which the Commission may take into account to rebut the presumptions laid down in Article 3(2) of the DMA. They are, in actual fact, additional elements which confirm those presumptions or which could justify designation under Article 3(8) of the DMA.

188In that regard, it is sufficient to note that the Commission took into account the benefits associated with the existence of Microsoft’s ecosystem not as elements capable of rebutting the presumption laid down in Article 3(2)(b) of the DMA, but, on the contrary, as elements which could contribute to making Edge an important gateway. As is apparent from the case-law referred to in paragraphs 180 and 182, the benefits or disadvantages associated with the existence or absence of an ecosystem are part of the relevant factors for assessing whether the CPS in question constitutes an important gateway.

189Second, the applicant maintains that Edge’s scale of usage on personal computers using Windows PC OS is considerably greater than on mobile devices, which shows that Microsoft’s practices confer an artificial advantage on Edge. That advantage also stems from the fact that, because of Edge’s pre-installation on devices equipped with Windows PC OS, Edge enjoys a status quo bias, in the sense that users tend to use software that is pre-installed or set as the default, rather than download an alternative product.

190In that regard, first, it is apparent from paragraphs 102 to 105 above that the importance of web browsers cannot be assessed by reference to a single group of devices or operating systems by which they are offered. Consequently, even if, because of its integration into Microsoft’s ecosystem, Edge has become for certain devices – namely those using Windows PC OS – a web browser the importance of which is greater than that which it would have had in the absence of that integration, that fact alone is not decisive for the purposes of examining whether the presumption laid down in Article 3(2)(b) of the DMA is rebutted.

191Second, even for devices using Windows PC OS, Microsoft’s ecosystem played only a limited role in encouraging the use of Edge. Admittedly, it is not disputed that Microsoft’s practices promoted the use of Edge on those devices. The fact remains that, despite those practices, the scale of usage of Edge on such devices remained limited; in particular, it was significantly lower than that of Chrome and similar to that of Firefox, as is apparent from footnote 50 to recital 53 of the contested decision.

192It follows that Microsoft’s various practices to promote the use of Edge on devices equipped with Windows PC OS did not confer an advantage sufficiently significant, in particular in terms of contestability, to call into question the Commission’s conclusion that Microsoft demonstrated that it did not satisfy the requirements laid down in Article 3(1)(b) of the DMA as regards Edge.

193Third, the applicant submits that the ‘artificial’ advantages enjoyed by Edge on personal computers are further emphasised by the fact that its share of supply on such devices in Europe increased from 0% at the time of its launch in 2015 to approximately 14% in 2024.

194However, as observed in paragraph 114 above, that argument is based on an incorrect premiss, since the increase in Edge’s use was to the detriment of another Microsoft web browser which Edge replaced, namely Internet Explorer, and not to the detriment of the web browsers of other providers.

195Fourth, the applicant claims that Edge is an important lever to drive up the usage of other Microsoft products, such as its online search engine Bing. In that regard, it is apparent from the contested decision that between 70% and 80% of all average monthly search queries on Bing are made by means of Edge. More generally, between 80% and 90% of all the searches carried out on Bing are carried out on devices using Windows.

196In that connection, the Commission’s finding set out in recital 66 of the contested decision that Microsoft’s ability to use Edge as a lever to promote Bing was limited and insufficient for Edge to be regarded as an important gateway is based on the low scale of usage of Bing in the European Union, which was between 3% and 5% on all types of devices. Even assuming that the data referred to by the applicant show that Bing benefited from being integrated into Edge, those data are not decisive as regards the question whether Edge is an important gateway, since they do not relate, inter alia, to the size of Bing in relation to other search engines, or to Edge’s ability significantly to increase the use of Bing by comparison with those engines. In those circumstances, the applicant’s argument must be rejected.

197That is all the more the case since the applicant does not dispute that, as stated in recital 25 of the contested decision, the scale of usage of Bing remained very limited by comparison with Google Search during the period from 2020 to 2022, which shows that Microsoft has not succeeded in using Edge to drive up the scale of usage of Bing significantly.

198Fifth, the applicant maintains that the reasoning in the contested decision based on Chrome’s scale of usage being higher than that of Edge on devices using Windows PC OS is irrelevant. The fact that Chrome may offset the advantage arising from Edge’s pre-installation does not mean that other web browsers, such as Opera, are also able to do so.

199That argument is factually incorrect since other web browsers succeeded in offsetting the advantage deriving from Edge’s pre-installation on Windows PC OS. That is in particular true in the case of Firefox, the scale of usage of which is approximatively 10% to 20% on personal computers equipped with Windows PC OS, whereas the scale of usage of Edge is 20% to 30% on those devices, as is apparent from the information in footnote 50 to recital 53 of the contested decision, which the applicant did not dispute. Furthermore, as regards the scale of usage of web browsers on all devices, it is apparent from recitals 54 and 55 of the contested decision that Firefox’s scale of usage was, according to the three data sources relied on, 6.4%, 9.1% or 5.4%, respectively, whereas Edge’s scale of usage was, according to the same sources, 3.9%, 5.6% or 5.8%, respectively.

200Sixth, the applicant criticises the contested decision, maintaining that it allows Microsoft to continue to resort to practices aimed at increasing the use of Edge, which could escape competition law scrutiny. That decision thus created an exceptional situation in which the platform which most aggressively promotes a given web browser is the only relevant platform on which users and competitors do not get the benefit of a browser choice screen.

201In that regard, it is sufficient to note that, by those arguments, the applicant criticises the alleged consequences of the non-designation of Microsoft as a gatekeeper as regards Edge, but does not call into question the grounds on which the contested decision is based. Therefore, those arguments must be rejected.

202It follows from the foregoing that the applicant has not shown that the Commission made an error of assessment in taking the view that the advantages associated with Edge’s integration into Microsoft’s ecosystem were not sufficiently significant for it to be regarded as an important gateway.

203That is all the more the case for the reasons stated in recital 67 of the contested decision, the main points of which were set out in paragraph 21 above. Following Microsoft’s designation as a gatekeeper in respect of its Windows PC OS operating system in Commission Decision C(2023) 6106 final, Article 6(3) of the DMA requires Microsoft to allow and technically enable end users easily to uninstall any software applications on its operating system and easily to change default settings on that system. Consequently, as the Commission maintains before the Court, the changes imposed by Article 6(3) of the DMA are such as to weaken further Microsoft’s ability to use its ecosystem to drive up Edge usage.

204In that regard, the applicant appears to maintain that it is not certain that Microsoft will comply with Article 6(3) of the DMA and that the Commission could therefore not take that element into account when assessing whether Edge should be regarded as an important gateway.

205In addition to the fact that the applicant has not adduced any evidence in support of its argument, it should be recalled that Articles 30 and 31 of the DMA confer on the Commission the power to impose fines and periodic penalty payments on gatekeepers in the event of non-compliance with the obligation laid down in Article 6(3) of the DMA. Therefore, gatekeepers have an incentive to comply with that obligation.

206The applicant also claims that the web browsers Chrome and Safari, operated by Alphabet and Apple, respectively, have been designated as important gateways, regardless of the fact that those browsers also have to comply with Article 6(3) of the DMA so far as concerns their respective operating systems, namely Android and iOS, for which they have also been designated as gatekeepers.

207In that regard, it is sufficient to note that the Commission is required to carry out an individual appraisal of the circumstances of each case, without being bound by previous decisions concerning other undertakings or other CPSs, as has been pointed out in paragraph 97 above. In any event, as noted in paragraph 78 above, the web browsers Chrome and Safari were the two most important browsers in the light of the scale of usage.

208In the light of all of the foregoing, the third part of the single plea in law must be rejected.

The fourth part of the single plea, alleging that the Commission erred in finding that the grounds of the contested decision were sufficient to rebut the presumption laid down in Article 3(2)(b) of the DMA

209The applicant maintains that the grounds relied on by Microsoft and accepted in the contested decision are not sufficient to rebut the presumption laid down in Article 3(2)(b) of the DMA. In the applicant’s view, in the light of the principle of good administration, the Commission could not limit its assessment solely to the elements relied on by Microsoft to rebut that presumption, but should have taken into account all the relevant factors concerning Edge’s importance, in particular those set out in Article 3(8) of the DMA.

210In that regard, there is no difference between, on the one hand, a market investigation concerning the rebuttal of the presumptions pursuant to Article 3(5) of the DMA, when the thresholds laid down in Article 3(2) of the DMA are met, and, on the other hand, a market investigation conducted under Article 3(8) of the DMA, where those thresholds are not met. According to the applicant, any market investigation carried out under Article 17 of the DMA must take into account the relevant qualitative elements, since all gatekeeper designations, whether or not they are based on the presumptions laid down in Article 3(2) of the DMA, are ultimately designations based on the criteria set out in Article 3(1) of the DMA.

211In addition, undertakings that meet the thresholds set out in Article 3(2) of the DMA and that seek to rebut the presumptions laid down in that provision should not be in a more favourable position to avoid being designated as gatekeepers than those which, although they do not meet those thresholds, may be designated as such in the light of the elements listed in Article 3(8) of the DMA.

212The Commission, supported by Microsoft, disputes that line of argument.

213As a preliminary point, it is necessary to draw a distinction between two procedures for designating gatekeepers established in Article 3 of the DMA.

214First, pursuant to Article 3(4) of the DMA, the Commission designates as a gatekeeper an undertaking providing CPSs that meets all the thresholds in Article 3(2) of the DMA (‘quantitative designation’).

215However, the first subparagraph of Article 3(5) of the DMA provides that the undertaking providing CPSs may present, with the notification under the first subparagraph of Article 3(3) of the DMA, sufficiently substantiated arguments to demonstrate that, exceptionally, although it meets all the thresholds laid down in Article 3(2) of the DMA, due to the circumstances in which the relevant CPS operates, it does not satisfy the requirements listed in Article 3(1) of the DMA.

216Pursuant to the second subparagraph of Article 3(5) of the DMA, where the Commission considers that the arguments submitted pursuant to the first subparagraph of Article 3(5) of the DMA by the undertaking providing CPSs are not sufficiently substantiated because they do not manifestly call into question the presumptions set out in Article 3(2) of the DMA, it may reject those arguments within the time limit referred to in Article 3(4) thereof, without opening a market investigation pursuant to Article 17(3) of the DMA.

217By contrast, in accordance with the third subparagraph of Article 3(5) of the DMA, where the undertaking providing CPSs does present such sufficiently substantiated arguments manifestly calling into question the presumptions laid down in Article 3(2) of the DMA, the Commission may, within the same time limit, open a market investigation pursuant to Article 17(3) of the DMA.

218According to the fourth subparagraph of Article 3(5) of the DMA, if the Commission concludes that the undertaking providing CPSs has not been able to demonstrate that the CPSs it provides did not satisfy the requirements of Article 3(1) of the DMA, it is to designate that undertaking as a gatekeeper in accordance with the procedure laid down in Article 17(3) of the DMA.

219Second, under the first and second subparagraphs of Article 3(8) of the DMA, the Commission is to designate as a gatekeeper, in accordance with the procedure laid down in Article 17 of the DMA, any undertaking providing CPSs that meets each of the requirements of Article 3(1) of the DMA, but does not satisfy each of the thresholds in Article 3(2) of the DMA (‘qualitative designation’). For that purpose, the Commission is to take into account some or all of the elements listed in points (a) to (g) of the second subparagraph of Article 3(8) of the DMA, in so far as they are relevant in relation to the undertaking concerned.

220In that context, paragraphs 1 to 3 of Article 17 of the DMA, which is entitled ‘Market investigation for designating gatekeepers’, confirm the distinction between quantitative and qualitative designations set out in Article 3 of the DMA. In that respect, it is apparent from the very wording of Article 17 of the DMA that paragraphs 1 and 2 of that article apply to qualitative designations, whereas paragraph 3 thereof applies to quantitative designations. Those provisions also lay down different time limits for market investigations carried out under those two procedures. The Commission thus has an indicative period of 12 months to conclude a market investigation carried out for the purposes of a qualitative designation and 5 months to conclude such an investigation in the context of a quantitative designation.

221Having made those clarifications, it should be noted that, in the context of a quantitative designation, which is that at issue in the present case, it is apparent from the fourth subparagraph of Article 3(5) of the DMA, read in conjunction with recital 23 thereof, that, during a market investigation carried out under Article 17(3) of the DMA, it is for the undertaking concerned to adduce evidence to show that the CPS it provides does not satisfy the requirements of Article 3(1) of the DMA.

222However, as in any administrative procedure, the Commission must respect the general principle of good administration, enshrined in Article 41 of the Charter of Fundamental Rights, when conducting a market investigation under Article 17(3) of the DMA and when adopting its closing decision.

223Under the principle of good administration, the Commission must conduct its market investigation diligently and impartially, so that it has at its disposal, when adopting the final decision, the most complete and reliable information possible for that purpose (see, to that effect, judgment of 10 November 2022, Commission v Valencia Club de Fútbol, C‑211/20 P , EU:C:2022:862 , paragraph 78 ).

224Accordingly, the Commission may not confine itself to assessing the arguments and evidence adduced by the undertaking seeking to rebut the presumptions laid down in Article 3(2) of the DMA and to demonstrating that that undertaking does not satisfy the requirements set out in Article 3(1) of the DMA, but must, as a matter of good administration, play its part, using the means available to it, in ascertaining the relevant facts and circumstances in order to carry out an appropriate assessment concerning the rebuttal of those presumptions (see, by analogy, judgments of 13 July 1966, Consten and Grundig v Commission, 56/64 and 58/64 , EU:C:1966:41 , p. 347 ; of 29 February 2016, Deutsche Bahn and Others v Commission, T‑267/12 , not published, EU:T:2016:110 , paragraph 68 ; and of 29 February 2016, Schenker v Commission, T‑265/12 , EU:T:2016:111 , paragraph 65 ).

225This is all the more so since the Commission has investigative powers which it may apply, inter alia, in the context of a market investigation carried out under Article 17(3) of the DMA (see, to that effect and by analogy, judgment of 16 May 2018, Deutsche Lufthansa v Commission, T‑712/16 , EU:T:2018:269 , paragraph 120 ).

226In particular, the Commission may, in accordance with Article 21 of the DMA, require undertakings and associations of undertakings to provide all necessary information. Similarly, under Article 22(1) of the DMA, the Commission may interview any natural or legal person which consents to being interviewed, for the purpose of collecting information, relating to the subject matter of an investigation.

227It follows that the Commission is required to take into account not only the information provided by the undertaking concerned and by the participants in the market investigation, but also other information which appears relevant for assessing whether that undertaking has demonstrated that it does not satisfy the requirements laid down in Article 3(1) of the DMA, which the Commission has or could reasonably have had at its disposal.

228Thus, it is not for the Commission to seek, on its own initiative and in the absence of any evidence to that effect, all the information which might be connected with the case before it.

229In addition, as noted in paragraph 221 above, the burden of proof for rebutting the presumptions established by Article 3(2) of the DMA lies with the undertaking concerned. However, by virtue of the Commission’s obligation referred to in paragraph 227 above, it may be required to take into consideration certain elements other than those provided by the undertaking concerned and by the participants in the market investigation, when it assesses the merits and relevance of the arguments and evidence which that undertaking submitted with a view to rebutting those presumptions.

230The applicant’s arguments must be examined in that context.

231In the first place, the applicant maintains that the Commission confined itself to examining the arguments put forward by Microsoft to rebut the presumption laid down in Article 3(2)(b) of the DMA, and that it failed to take into consideration and investigate other relevant circumstances that could have confirmed that Edge was an important gateway.

232In that regard, it is apparent from recital 42 of the contested decision that Microsoft put forward three sets of arguments aimed at demonstrating that, although it meets all the thresholds laid down in Article 3(2) of the DMA, in relation to Edge, it exceptionally did not satisfy the requirements listed in Article 3(1) of the DMA.

233First, as is apparent from recitals 43 and 44 of the contested decision, Microsoft claimed that Edge was not an important gateway because of its relatively small scale, given (i) the overall scale of its activities in the web browser CPS category and (ii) its size in comparison with other web browsers offered in the European Union.

234Second, as stated in recitals 45 to 47 of the contested decision, Microsoft maintained that it was necessary to take account of the close connections between Edge, on the one hand, and Bing and Microsoft Advertising, on the other. In order to determine whether Edge was an important gateway, account should be taken not only of its own underperformance, but also of that of Bing and Microsoft Advertising. Account should also be taken of the fact that Edge is dependent on the browser engine Blink.

235Third, as is apparent from recital 48 of the contested decision, Microsoft also submitted that the number of active yearly business users was not a reliable indicator of Edge’s importance for those undertakings. Similarly, the number of active monthly end users does not reflect the actual use of Edge properly and does not take account of multi-homing in the web browser CPS category. Furthermore, the designation of Microsoft as a gatekeeper in relation to Edge does not facilitate contestability under the DMA, but rather further entrenches the position of gatekeepers providing web browser CPSs and online search engine CPSs.

236It is apparent both from the contested decision and from the file before the Court that the Commission did not confine itself to examining Microsoft’s arguments set out in paragraphs 233 to 235 above, but also took into account other relevant factors in order to assess whether Microsoft had demonstrated that it did not satisfy the requirements of Article 3(1)(b) of the DMA.

237In that connection, first of all, it follows from recitals 63 to 68 of the contested decision, the main points of which were set out in paragraphs 16 to 22 above, that the Commission examined whether the integration of Edge into Microsoft’s ecosystem and the practices implemented by Microsoft within its ecosystem, with a view to increasing the use of Edge, ought to have led to that browser being regarded as an important gateway.

238Next, it is apparent from recitals 57 and 69 of the contested decision that the Commission investigated whether Edge could benefit from advantages linked to the use of artificial intelligence, as is moreover confirmed by Question D.12 of the request for information sent to competitors.

239In addition, it is apparent from Questions D.1, D.2 and D.4 to D.7 of the request for information sent to competitors that the Commission examined whether Edge had certain particularly important characteristics, such as private web browsing, password management, cookie blocking or form auto-fill.

240Furthermore, on 20 September 2023, the Commission sent a request for information to business users, which is included in the Court’s file as Annex C.1 to the defence, from which it is apparent that it examined whether Edge was particularly important for certain groups of business users in order for them to offer their services. This follows, in particular, from the questions in that request under the heading ‘C. Questions to Website owners’, and in particular Questions C.8 to C.14 and C.16, the questions under the heading ‘D. Questions to Extension providers’, and in particular Questions D.6 to D.12, D.14 and D.20, as well as the questions under the heading ‘E. Questions to Web app providers’, in particular Questions E.6 to E.12, E.14 and E.20.

241Lastly, by the request for information of 20 September 2023 addressed to other undertakings active on the market, which is included in the Court’s file as Annex C.2 to the defence, the Commission also investigated whether Edge was particularly important for certain groups of business users in order for them to offer their services. This is apparent from the questions under the heading ‘C. Questions for Website developers’, in particular Questions C.1 to C.3, C.6, C.7, C.12, C.14 and C.18, as well as the questions under the heading ‘D. Questions for Web app developers’, in particular Questions D.1 to D.3, D.6, D.7, D.12, D.14 and D.18.

242It follows from the foregoing that the complaint that the Commission confined itself to examining the arguments put forward by Microsoft during its market investigation has no factual basis.

243In the second place, the applicant submits that the Commission was required to take into account the elements listed in Article 3(8) of the DMA when it examined, in the context of the market investigation, Microsoft’s arguments seeking to rebut the presumptions laid down in Article 3(2) of the DMA.

244In that regard, first of all, it follows from the wording of Article 3(8) of the DMA, as recalled in paragraph 219 above, that that provision applies to qualitative designation, namely the situation in which the undertaking concerned ‘does not satisfy each of the thresholds in [Article 3(2) of the DMA]’, with the result that that wording alone does not lead to the conclusion that the Commission is required to examine the elements listed therein in the context of a quantitative designation.

245Next, concerning the purpose of Article 3(8) of the DMA, it is apparent from recitals 73 and 74 thereof that the EU legislature wished to provide for qualitative designations in order to ensure the full and lasting achievement of the objectives of the DMA, by ensuring that the Commission is able to designate as a gatekeeper an undertaking that fulfils all of the overarching qualitative criteria for being identified as such, without it however reaching the quantitative thresholds laid down in Article 3(2) of the DMA. It cannot however be inferred therefrom that the Commission is systematically required to take account of the elements listed in Article 3(8) of the DMA in the context of quantitative designations.

246Furthermore, as regards the general scheme of the DMA, the applicant cannot claim that Article 17 thereof provides for a single procedure for the designation of gatekeepers, with the result that the Commission must take account of the same elements in any designation procedure, namely, inter alia, those listed in Article 3(8) of the DMA. As has been noted in paragraph 220 above, it is apparent from the very wording of Article 17 of the DMA that paragraphs 1 and 2 thereof apply to qualitative designations, whereas paragraph 3 applies to quantitative designations.

247Lastly, as regards the legislative history of the DMA, the proposal for a regulation of the European Parliament and of the Council on contestable and fair markets in the digital sector (Digital Markets Act) of 15 December 2020 (COM(2020) 842 final) expressly provided, in Article 3(4) and (6) thereof, for the same criteria to be applied in the context of quantitative and of qualitative designations, it being understood that those criteria corresponded, in essence, to those laid down in Article 3(8) of the DMA. However, it is apparent from the wording of Article 3(5) and (8) of the DMA that the EU legislature after all chose not to provide for such consistency between those two types of designations.

248In those circumstances, Article 3 of the DMA must be interpreted as meaning that the Commission is not systematically required to take into account the elements set out in Article 3(8) of the DMA when conducting a market investigation under Article 17(3) of the DMA in the context of the rebuttal of the presumptions laid down in Article 3(2) of the DMA.

249However, in the light of the considerations set out in paragraphs 222 to 229 above, the Commission may be required, under the principle of good administration, to take account of certain elements which coincide with those provided for in Article 3(8) of the DMA and which are not raised by the undertaking concerned and the participants in the market investigation, but which are or could reasonably have been available to it, where those elements appear relevant for assessing whether that undertaking has demonstrated that it does not satisfy the requirements set out in Article 3(1) of the DMA.

250It is in that context that the Court must examine the applicant’s line of argument, which is based on the Commission’s failure to take into account the elements corresponding to those provided for in Article 3(8) of the DMA.

251In that regard, first, the applicant submits that the Commission should have taken into consideration the extent to which, and the period of time during which, Edge exceeded the thresholds relating to the number of end users and business users laid down in Article 3(2)(b) of the DMA.

252First of all, it is apparent from recital 56 of the contested decision that the participants in the market investigation maintained that it was for the Commission to take account of the large number of Edge end users. In response, the Commission took the view, in the same recital, that the market investigation had demonstrated that, irrespective of the high number of end users, Edge’s scale of usage compared to other web browsers was significantly lower. In those circumstances, the applicant cannot criticise the Commission for not having taken into account the extent to which the number of end users had exceeded the thresholds laid down in Article 3(2)(b) of the DMA.

253Next, as regards the extent to which the number of business users exceeded those thresholds, the contested decision does not mention that element. Nevertheless, as is apparent from Section E of the annex to the DMA, business users of web browsers are, inter alia, those who have a business website or those who offer a plug-in, extension or add-ons used on a web browser. As the Commission explained at the hearing, the number of such undertakings is the same for all web browsers. In those circumstances, the Commission was entitled to take the view that that element was not particularly relevant for determining whether a given browser was an important gateway.

254Lastly, so far as concerns the number of years during which the thresholds relating to the number of users laid down in Article 3(2)(b) of the DMA were exceeded, it is apparent from Article 3(2)(c) of the DMA that that element is rather – as the Commission rightly points out – covered by the condition laid down in Article 3(1)(c) of the DMA for designating an undertaking as a gatekeeper, that is to say, that it must enjoy an entrenched and durable position in its operations, and not the condition laid down in Article 3(1)(b) of the DMA, which concerns the importance of the CPS as an important gateway.

255In the contested decision, the Commission found that there was no need to designate Microsoft as a gatekeeper in relation to Edge, since Edge was not an important gateway within the meaning of Article 3(1)(b) of the DMA.

256In the present case, the applicant does not explain how the number of years during which the user number thresholds laid down in Article 3(2)(b) of the DMA were exceeded is relevant for assessing whether Edge satisfies the condition referred to in paragraph 255 above.

257In those circumstances, the applicant cannot criticise the Commission for not having taken account of the elements referred to in paragraph 251 above.

258Second, the applicant claims that the Commission focused on the intensity of use of Edge by end users, to the exclusion of other relevant elements. Those include, inter alia, the overall number of end users and business users, the number of devices on which Edge is installed, the advantages enjoyed by Edge thanks to its pre-installation on devices using Windows, its default setting on those devices and its distribution on those devices, and the fact that Edge is the only browser developed by a vertically integrated gatekeeper which is not subject to the obligation to present a web browser choice screen pursuant to Article 6(3) of the DMA.

259In that regard, first of all, it should be noted that the present argument is based on an incorrect premiss, since, as is apparent from paragraphs 231 to 242 above, the Commission did not focus exclusively on the intensity of use of Edge.

260Next, as regards the overall number of end users and of business users, and the number of devices on which Edge is installed, the applicant does not explain how those elements go beyond those referred to in paragraph 251 above and examined in paragraphs 252 and 253 above.

261As regards the pre-installation, default setting and distribution of Edge on devices using Windows, it is apparent from recitals 63 to 68 of the contested decision that the Commission took those elements into account. Moreover, as the Commission rightly maintains, Questions D.3 and D.8 to D.10 of the request for information sent to competitors concerned Edge’s pre-installation and default setting and, more generally, Microsoft’s ecosystem. The same applies to Question F.1 of the request for information of 20 September 2023 addressed to other undertakings active on the market.

262Lastly, the applicant has failed to explain why the fact that Edge is the only browser developed by a vertically integrated gatekeeper which is not subject to the obligation to present a web browser choice screen pursuant to Article 6(3) of the DMA should result in it being regarded as an important gateway.

263Third, the applicant maintains that, contrary to the requirements of Article 3(8)(a) of the DMA, the Commission did not take into account Microsoft’s size, including its turnover and market capitalisation, its operations and its position.

264In that regard, as recalled in paragraph 255 above, the contested decision is based on the finding that Edge does not constitute an important gateway within the meaning of Article 3(1)(b) of the DMA.

265As the Commission rightly points out, it is apparent from Article 3(2)(a) of the DMA that Microsoft’s size, including its turnover and market capitalisation, as well as its activities and position are elements which relate in particular to the condition laid down in Article 3(1)(a) of the DMA for designating an undertaking as a gatekeeper, namely its significant impact on the internal market, and not to that relating to the importance of the CPS as an important gateway. Despite that, the applicant does not explain how those elements relate to the importance of Edge as an important gateway within the meaning of Article 3(1)(b) of the DMA.

266Fourth, the applicant takes the view that, in accordance with Article 3(8)(c) of the DMA, the Commission ought to have taken into consideration network effects and the data-driven advantages deriving from data held by Microsoft (‘the data-driven advantages’), in particular in relation to Microsoft’s and Edge’s access to, and collection of, personal data and non-personal data and Microsoft’s analytics capabilities.

267In that regard, it is true that, in the contested decision, the Commission did not examine the relevance of those elements. However, as regards network effects, the applicant merely mentions that element, as it appears in Article 3(8)(c) of the DMA, without explaining what the alleged network effects enjoyed by Edge are. As far as concerns the data-driven advantages, the applicant merely maintains that Edge collects large amounts of those data and that Microsoft has ‘top-of-the-industry’ analytics capabilities in respect of those data. Microsoft uses such data to provide its software, services and devices, offer targeted advertising and develop artificial intelligence and machine-learning systems.

268By confining itself to making such assertions, the applicant fails to explain how network effects or the data-driven advantages could be relevant for assessing whether Microsoft had demonstrated that Edge was not an important gateway.

269In any event, it cannot be established from the applicant’s line of argument that the Commission had any specific evidence that demonstrated such relevance. In particular, it does not claim that the Commission failed to take into account any element or evidence relating to network effects or the data-driven advantages that is apparent from its response to the request for information sent to competitors. However, Question F.3 of that request enabled it to submit any comment that might be relevant for assessing whether Microsoft had demonstrated that it did not meet the requirements laid down in Article 3(1) of the DMA.

270Fifth, the applicant maintains that the Commission should have taken account of any scale and scope effect from which Microsoft benefits as a result of its ecosystem.

271By that argument, the applicant repeats, in essence, part of its line of argument formulated in the context of the third part of the single plea in law (see paragraphs 174 and 189 above), without explaining how the present argument goes further than that line of argument. It must therefore be rejected on the same grounds as those set out in paragraphs 181 to 186 and 190 to 192 above.

272Sixth, the applicant submits that the Commission should have taken into account business-user or end-user lock-in, including switching costs and behavioural bias reducing the ability of business users and end users to switch or multi-home. In particular, the Commission failed to take into consideration the theory of behavioural bias and consumer inertia, that is to say, aspects which were considered relevant in the context of pre-installation and default setting of an application on a given platform in Commission Decision C(2018) 4761 final of 18 July 2018 relating to a proceeding under Article 102 [TFEU] and Article 54 of the EEA Agreement (Case AT.40099 – Google Android).

273In that regard, it is sufficient to recall that the Commission took Edge’s pre-installation and default setting on Microsoft into account both in the market investigation and in the contested decision (see paragraph 261 above). Furthermore, the applicant does not explain how its argument based on the theory of behavioural bias goes beyond that which was summarised in paragraph 189 above and examined in paragraphs 190 and 191 above.

274As to the remainder, the applicant merely cites the wording of Article 3(8)(e) of the DMA, without explaining how the elements referred to therein could be relevant for assessing whether Microsoft had demonstrated that Edge was not an important gateway.

275In any event, the applicant’s line of argument does not establish that the Commission had any specific evidence showing the relevance of an element which it had omitted in the course of its examination.

276Seventh, the applicant takes the view that the Commission failed to examine Edge’s high monetisation potential, which is nonetheless a relevant factor, according to recital 17 of the DMA, in assessing whether a CPS is an important gateway. In that regard, according to the second paragraph of that recital, the monetisation potential of a CPS reflects ‘in principle … the gateway position of the undertakings concerned’.

277However, the applicant merely links Edge’s monetisation potential to the other services forming part of Microsoft’s ecosystem, such as the search engine Bing. By that argument, the applicant reiterates, in essence, part of its line of argument formulated in the context of the third part of the single plea in law (see paragraphs 174, 175 and 195 above), without explaining in sufficient detail how the present argument goes further than that line of argument.

278In any event, the applicant’s line of argument does not make it possible to determine how Edge’s monetisation potential is relevant for assessing whether Microsoft had demonstrated that Edge was not an important gateway.

279Moreover, that line of argument does not make it possible to establish that the Commission had any specific evidence showing such relevance. In particular, as noted in paragraph 269 above, the applicant does not claim that the Commission failed to take into account an element or evidence linked to Edge’s monetisation potential that is apparent from its response to the request for information sent to competitors.

280Similar considerations apply to the applicant’s eighth argument, by which it claims that the Commission should have taken into account foreseeable developments concerning the elements listed in Article 3(8) of the DMA.

281In that regard, the applicant does not provide any details as to the foreseeable developments which the Commission should have taken into account, or as to the evidence it holds in that respect, with the result that its argument is not substantiated.

282In addition, it is apparent from recitals 57 and 69 of the contested decision that the Commission took into account at least one foreseeable development, namely the future impact which integrating artificial intelligence functionalities into Edge may have on the importance of Edge as a gateway.

283In the light of all of the foregoing, it must be held that the applicant has not succeeded in establishing that the Commission did not have sufficient, complete and reliable evidence, within the meaning of the case-law referred to in paragraph 223 above, to support the finding that Microsoft had demonstrated that Edge does not constitute an important gateway.

284In any event, similarly to what the Court held in the judgment of 17 July 2024, Bytedance v Commission ( T‑1077/23 , under appeal, EU:T:2024:478 , paragraph 336 ), the applicant has not put forward any specific argument capable of demonstrating that the conclusion reached by the Commission would have been different if it had assessed certain elements on which the applicant had relied for the purposes of the present part of the plea.

285In those circumstances, the fourth part of the single plea in law must be rejected.

The applications for measures of organisation of procedure or for measures of inquiry

286The applicant made several applications for measures of organisation of procedure and measures of inquiry, which it grouped together in Annex E.2 to its observations on Microsoft’s statement in intervention.

287In that regard, it is apparent from Article 89(1) of the Rules of Procedure that the purpose of measures of organisation of procedure is to ensure that cases are prepared for hearing, procedures carried out and disputes resolved under the best possible conditions. Measures of inquiry under Article 91 of the Rules of Procedure are intended to prove the truth of the factual claims made by a party in support of its pleas in law.

288According to the case-law, the Court is the sole judge of any need to supplement the information available to it in respect of the cases before it. It is therefore for the Court alone to assess the relevance of an application for measures of organisation of procedure or of inquiry in respect of the subject matter of the proceedings and the need to proceed therewith (see judgment of 21 November 2024, UG v Commission, C‑546/23 P , EU:C:2024:975 , paragraph 127 and the case-law cited).

289In the present case, in the first place, in its observations on the Commission’s plea of inadmissibility, the applicant asks the Court to order the Commission to produce the requests for information which it sent to the participants in the market investigation and their replies. Producing such requests is necessary in order to examine the Commission’s argument that the applicant’s competitors responded more fully to those requests.

290In that connection, the Court considers that it has sufficient information from the documents in the file and from the hearing to assess the nature of the applicant’s participation in the market investigation and, more generally, to determine whether it is individually concerned by the contested decision.

291In the second place, the applicant maintains that the Commission relied, in its defence, on several documents which were not communicated to the Court, such as Microsoft’s notification submitted to the Commission in accordance with the first subparagraph of Article 3(3) of the DMA and the annexes thereto or the replies of Microsoft and other participants in the market investigation to the requests for information. Thus, the applicant asks the Court either to reject as ineffective or inadmissible the arguments based on those documents, or to order that they be produced.

292While it is true that the Commission cannot rely on documents to which neither the Court nor the applicant has had access, that circumstance alone does not, as such, justify an order by the Court for the production of such documents. The Court may order such a measure for the organisation of procedure only if the applicant makes out a plausible case that those documents are necessary and relevant for the purposes of judgment (see, to that effect, judgment of 7 May 2009, NVV and Others v Commission, T‑151/05 , EU:T:2009:144 , paragraph 218 and the case-law cited).

293As is apparent from the examination of the applicant’s single plea in law, the Court is in a position to assess the merits of the action in the light of the grounds of the contested decision, the arguments and evidence submitted by the parties and the replies to the measures of organisation of procedure of 9 September 2025 and the questions put at the hearing.

294In those circumstances, it is neither necessary nor relevant to order the production of the documents referred to in paragraph 291 above in order to rule on the action.

295In the third place, in its observations on Microsoft’s application to intervene, the applicant asks the Court to order Microsoft to produce certain documents to which it referred to justify its intervention in the present case, such as the replies to the requests for information sent by the Commission during the market investigation. The production of those documents is necessary in order to ascertain whether the Commission complied with the principle of good administration and whether a failure to comply with that principle is capable of altering the conclusion that Edge is not an important gateway.

296For the same reasons, the applicant requests the Court to order Microsoft to produce any material that is directly relevant to determining whether the Commission erred in concluding that Microsoft exceptionally did not meet the requirements set out in Article 3(1)(b) of the DMA in respect of Edge. In that context, the applicant provided a non-exhaustive list of such materials.

297In that regard, first of all, it should be noted that the applicant has not sufficiently explained in what way the measures of organisation of procedure or measures of inquiry referred to in paragraphs 295 and 296 above were necessary in order to ensure that the present case was prepared for hearing or to prove the truth of certain factual claims which the Court was called upon to rely on in its judgment.

298Next, the Court is in a position to examine the present action on the sole basis of the grounds of the contested decision, the arguments and evidence submitted by the parties and the replies to the measures of organisation of procedure of 9 September 2025 and the questions put at the hearing.

299Lastly, several applications for measures of organisation of procedure or of inquiry seek, in actual fact, that the Court re-examine, on the basis of the documents requested and of its own motion, the assessments set out in the contested decision. Such requests go beyond the scope of measures of organisation of procedure or inquiry as recalled in paragraph 287 above (see, to that effect, judgment of 14 June 2023, Polwax v Commission, T‑585/20 , EU:T:2023:332 , paragraph 35 and the case-law cited).

300In the light of the foregoing, there is no need to grant the applicant’s applications for measures of organisation of procedure or inquiry.

Conclusion

301In the light of all of the foregoing, the single plea in law is unfounded and must be rejected and, consequently, the action must be dismissed in its entirety.

Costs

302Under Article 134(1) of the Rules of Procedure, the unsuccessful party is to be ordered to pay the costs if they have been applied for in the successful party’s pleadings.

303Since the applicant has been unsuccessful, it must be ordered to bear its own costs and to pay those incurred by the Commission and by the intervener, in accordance with the forms of order sought by them.

On those grounds, THE GENERAL COURT (Eighth Chamber, sitting with five Judges)

hereby:

1.Dismisses the action;

2.Orders Opera Norway AS to pay the costs.

Van der Woude

De Baere

Petrlík

Kecsmár

Kingston

Delivered in open court in Luxembourg on 2 September 2026.

V. Di Bucci

Registrar

S. Papasavvas

President

Table of contents

Background to the dispute

Contested decision

Forms of order sought

Law

Admissibility of the action

Substance

The first part of the single plea, alleging that the contested decision is incorrectly based on Edge’s market share

The second part of the single plea, alleging that the contested decision is incorrectly based on Microsoft’s alleged lack of control of the relevant architecture of Edge

– Arguments of the parties

– Preliminary remarks

– The statement of reasons for the contested decision as regards Blink

– Whether the complaint, claiming that the contested decision is incorrectly based on Microsoft’s alleged lack of control of the relevant architecture of Edge, is well founded

The third part of the single plea, according to which the Commission erred in finding that Microsoft’s ecosystem did not sufficiently contribute to making Edge an important gateway

The fourth part of the single plea, alleging that the Commission erred in finding that the grounds of the contested decision were sufficient to rebut the presumption laid down in Article 3(2)(b) of the DMA

The applications for measures of organisation of procedure or for measures of inquiry

Conclusion

Costs

( *1 ) Language of the case: English.