OpenAI is reportedly considering accusing its largest backer, Microsoft, of anticompetitive practices as tensions escalate over the terms of their high-profile partnership, according to a Wall Street Journal report published Monday.

The report says OpenAI executives have discussed the possibility of seeking a federal antitrust review of their contract with Microsoft and launching a public campaign challenging aspects of the alliance.

Such a move could threaten to unravel one of the most consequential partnerships in the artificial intelligence industry. Microsoft has invested heavily in OpenAI since 2019, including a $1 billion initial investment and multi-billion dollar commitments tied to exclusive cloud rights and model access via its Azure platform.

At the core of the dispute is OpenAI’s transition into a public-benefit corporation, which reportedly requires Microsoft’s approval. Despite months of negotiations, the two companies have not reached consensus on key terms, including Microsoft’s future equity stake and profit-sharing arrangements.

According to a separate report by The Information, OpenAI has proposed that Microsoft hold a 33% stake in a restructured unit in exchange for waiving future profit rights. The company is also seeking to amend clauses that grant Microsoft exclusive rights to host its models on Azure, as it looks to diversify its infrastructure partners—potentially by adding Google Cloud to its computing ecosystem.

Microsoft, however, has not accepted OpenAI’s proposed terms and is reportedly requesting additional concessions.

In a joint statement to Reuters, the companies said: “Talks are ongoing and we are optimistic we will continue to build together for years to come.”

As OpenAI continues to grow in influence and capability, the outcome of these negotiations could reshape the competitive dynamics in the AI sector and test the limits of collaboration between Big Tech and its most promising startups.