Brazil's Administrative Council for Economic Defense (CADE) has initiated an antitrust investigation into Microsoft following a formal complaint from Norwegian browser developer Opera. The complaint alleges that Microsoft's practice of pre-installing its Edge browser as the default on Windows devices unfairly restricts competition in the browser market.
Background
Opera's grievance centers on Microsoft's bundling of Edge with its Windows operating system. The company contends that this strategy impedes users from easily accessing alternative browsers, thereby granting Edge an undue market advantage. As of June 2025, Opera held a 6.78% share of Brazil's desktop browser market, while Edge accounted for 11.52%, trailing behind Google Chrome's dominant 75% share.Allegations Against Microsoft
Opera's complaint outlines several specific allegations:- Pre-installation Practices: Microsoft's default inclusion of Edge on Windows devices allegedly limits users' exposure to competing browsers.
- User Interface Design: The use of design tactics, often referred to as "dark patterns," purportedly discourages users from downloading and setting alternative browsers as default.
- Incentives to Manufacturers: Opera claims that Microsoft offers incentives to PC manufacturers to pre-install Edge exclusively, further restricting market access for rival browsers.
CADE's Investigation
In response to Opera's complaint, CADE has opened an administrative inquiry and has set an August 15 deadline for Microsoft to respond to the allegations. The investigation will examine not only the bundling of Edge but also Microsoft's licensing practices for its Windows operating system, Microsoft 365 software, and the Jumpstart AI program, which assists clients in building AI agents for routine tasks.Historical Context
This is not the first time Opera has challenged Microsoft's browser practices. In 2007, Opera filed a complaint with the European Commission regarding Microsoft's bundling of Internet Explorer with Windows, which resulted in a €561 million fine for Microsoft. The current complaint in Brazil echoes these past concerns, highlighting ongoing tensions between the two companies over market competition.Implications for the Browser Market
The outcome of CADE's investigation could have significant implications for the browser market in Brazil and potentially influence global practices. If Microsoft is found to have engaged in anti-competitive behavior, it may be required to alter its bundling practices, thereby creating a more level playing field for alternative browsers like Opera.As the investigation progresses, stakeholders in the tech industry will be closely monitoring developments, given the potential for this case to set precedents in antitrust enforcement related to software bundling and market competition.
Source: Storyboard18 Brazil opens antitrust probe into Microsoft after Opera's complaint over Edge browser
