OpenAI may file antitrust complaint against Microsoft

A serious conflict is brewing between OpenAI and its largest partner, Microsoft.

According to The Wall Street Journal, OpenAI’s leadership is considering filing an antitrust complaint against Microsoft — reportedly due to the tech giant’s growing attempts to tighten control over the startup and gain wider access to its technologies.

The dispute centers on the terms of OpenAI’s restructuring:

• Microsoft, which invested $13 billion into the company, is now seeking to increase its stake in OpenAI’s for-profit arm if the organizational structure changes. The company is also reportedly pushing for access to Windsurf technologies — the AI code editor startup OpenAI acquired for $3 billion in May 2025.
• OpenAI sees these demands as a threat to the company’s intellectual independence. One of the "hardline scenarios" under discussion is a formal complaint to U.S. regulators accusing Microsoft of anti-competitive practices, which could trigger a major antitrust investigation.
• Tensions between the two tech giants have been mounting since 2024, when The New York Times reported on Microsoft’s growing concerns about its reliance on OpenAI. At the same time, OpenAI was requesting additional resources to scale its products — including ChatGPT.
• In May 2025, OpenAI proposed a new governance model by transitioning to a Public Benefit Corporation (PBC), where control remains with the nonprofit board. However, this new structure requires Microsoft’s approval. Financial Times previously reported that Microsoft may be willing to give up part of its stake in exchange for continued access to OpenAI technologies — but no deal has been reached so far.

Sources close to WSJ emphasize that the antitrust complaint is being treated as a last resort — but is now being seriously discussed amid escalating tensions.