Microsoft's $135B OpenAI Stake Just Got a Lot More Complicated

The Microsoft-OpenAI marriage isn’t ending, but the prenup just got a major rewrite. The new definitive agreement outlines a vastly more complex relationship as OpenAI transforms into a public benefit corporation (PBC), a structure that lets it legally chase profits while claiming a public good mission. Microsoft now holds an investment in this new for-profit entity valued at roughly $135 billion, giving it about a 27 percent stake on a fully diluted basis, down from the 32.5 percent it held before recent funding rounds diluted its position.

The changes here aren’t cosmetic. The most interesting twist is a new governance mechanism: the momentous decision of when we’ve actually achieved Artificial General Intelligence (AGI) will no longer be a unilateral call by OpenAI’s board. An independent expert panel now gets to verify that declaration, a move that feels designed to prevent a repeat of the chaotic November 2023 boardroom drama that briefly ousted Sam Altman. This verification gate matters enormously because AGI is the tripwire that fundamentally alters the IP and commercial terms between the two companies.

Before AGI hits, the exclusive honeymoon continues. Azure remains the only place you can access OpenAI’s API, and Microsoft’s IP rights, which now explicitly carve out consumer hardware and some research methods, are extended through 2032. But OpenAI got some real breathing room. They can now build products with other partners, serve non-API stuff on any cloud they want, and release open-weight models that pass certain capability checks. The handcuffs are looser, even if the revenue sharing continues on a longer payment schedule.

Perhaps the most telling detail for infrastructure watchers is that Microsoft lost its right of first refusal on compute. OpenAI has instead committed to buying an additional $250 billion in Azure services, a staggering number that locks in a massive revenue stream for Microsoft while freeing OpenAI to shop for capacity elsewhere to feed its insatiable hunger for GPUs. Both companies can now independently chase AGI, with or without each other. What was once a simple patron-and-protégé story has officially become a rivalry between frenemies who are still contractually obligated to share a very expensive house.