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.

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.