Jan 10 (Reuters) - The U.S. Federal Trade Commission

weighed in on Friday on Elon Musk's lawsuit seeking to block

OpenAI's conversion to a public company, pointing out legal

doctrines that could support his claim that OpenAI and Microsoft ( MSFT )

engaged in anticompetitive practices.

While it did not officially support either side, the FTC

offered legal analysis that could aid Musk at a Tuesday hearing

in Oakland, California. Musk co-founded OpenAI and owns AI

startup xAI.

A spokesperson for Microsoft ( MSFT ) declined to comment. A

spokesperson for OpenAI did not immediately respond to a request

for comment.

The FTC is separately looking into partnerships in AI,

including between Microsoft ( MSFT ) and OpenAI, investigating

potentially anticompetitive conduct at Microsoft ( MSFT ) and probing

whether OpenAI violated consumer protection laws.

Musk alleges OpenAI violated antitrust law by making

investors agree not to invest in rival artificial intelligence

firms, and by sharing board members with Microsoft ( MSFT ), which is

also a defendant in the lawsuit.

OpenAI has said the board member claims are moot, because

Microsoft ( MSFT ) board member Reid Hoffman, who was on OpenAI's board,

and Microsoft ( MSFT ) executive Deannah Templeton, who had an observer

seat, are no longer affiliated with it.

But even after they leave boards, directors could still have

sensitive competitive information, the FTC said. Board members

who only have observer status are not exempt from the law, the

agency said in its brief.

Musk also claims that OpenAI facilitated a group investor

boycott against its rivals. Such claims are viable even when the

organizer of the boycott is not a member, the FTC said.