Brazil antitrust watchdog probes Microsoft after Opera complaint over edge browser practices

Brazil’s antitrust regulator CADE has opened an investigation into US tech giant Microsoft at the request of Norwegian browser firm Opera, which had filed a formal complaint with the regulator.

At stake in the inquiry is whether Microsoft has unfairly blocked its competitors from signing up users because its Edge browser is installed and set as the default on all systems that run Windows.

Like the complaint Opera filed Tuesday, the administrative inquiry, announced late Thursday in a CADE statement, is regarding the alleged monopoly on the browser market.

Opera claimed that Microsoft's practice of bundling Edge with Windows tilts the playing field against competing browsers, which Opera said is a violation of competition based on products.

The complaint cites June data showing Opera with a 6.78% share of Brazil's desktop browser market. Microsoft's Edge follows with 11.52%, and Google Chrome is at 75% share.

Opera has said that Microsoft's practices of framework integrations give Edge an unfair advantage, even with such a small market share.

CADE timeline and scope

CADE said Microsoft had until August 15 to react to the charges.

The regulator's investigation will focus not only on Edge bundling but also on Microsoft's broader commercial practices, including Windows licenses, Microsoft 365, and the company's Jumpstart program.

Jumpstart enables Microsoft clients to construct autonomous AI agents to execute mundane digital chores, as part of the company's overall AI monetisation strategy.

Other large tech companies have introduced similar tools, but CADE's focus on the initiative reflects a rising concern about how such products can further entrench dominant players.

The probe demonstrates how AI-related services are increasingly becoming subject to broader antitrust scrutiny, particularly when tied to already popular software platforms like Windows.

Opera’s long-running concerns

This is not Opera's first dispute with Microsoft about browser competition. In December 2007, Opera lodged a similar complaint with the European Commission, focusing on Microsoft's then-dominant Internet Explorer.

In 2013, the European Union concluded that Microsoft had failed to comply with a commitment to offer browser choices to Windows customers, resulting in an unprecedented €561 million ($640 million) fine.

The Brazilian instance recalls past concerns, but the environment has altered, with Edge replacing Internet Explorer and AI now playing an important part in product ecosystems.

Microsoft remains silent, for now

According to Reuters, Microsoft had not responded to emailed requests for comment on the CADE investigation.

The corporation has previously justified its software integration tactics as user-friendly, citing performance, security, and ease of use.

CADE's decision to formally launch an investigation demonstrates its readiness to examine how digital platforms may be reinforcing market dominance through product design and service bundling—particularly when smaller competitors raise concerns.

Broader implications for big tech

The Brazilian investigation is on top of a growing pile of global antitrust obstacles in the way of Microsoft and other tech companies.

As digital services have evolved into AI and productivity ecosystems, regulators are increasingly interested in whether or not default settings and bundled tools unfairly favour incumbents.

Although there are no formal charges, CADE's investigation could have downstream effects on the distribution and marketing of both browsers and AI tools inside Brazil's borders and potentially beyond.