The US’s two antitrust agencies sided with part of Elon Musk’s argument to block artificial intelligence startup OpenAI from restructuring as a for-profit company.

While they didn't support Musk's allegations directly, the feds added weight to his interpretation of antitrust law.

OpenAI launched a for-profit subsidiary a year later in order to raise outside capital, including more than $13 billion so far from its biggest backer, Microsoft. However, the non-profit entity, along with employees and investors, currently owns that for-profit subsidiary.

U.S. antitrust enforcers weighed in on Friday on Elon Musk's lawsuit seeking to block OpenAI's conversion to a public company, pointing out legal doctrines that support his claim that OpenAI and Microsoft engaged in anticompetitive practices.

A lawyer for billionaire Elon Musk has asked attorney generals in the states of California and Delaware to push OpenAI to auction a major stake in its business to decide fair value of its charitable asset during its corporate restructuring,