Musk dropped the lawsuit but filed another one against Altman and OpenAI, this time elevating his accusations to claim OpenAI worked with Microsoft, an investor, to create a monopoly. The billionaire also alleged the company violated its founding claim as a nonprofit by pursuing profit. OpenAI has denied the allegations.

Mr. Musk has fallen out with prominent right-wing Americans who say they are worried that their agenda may be sidelined in favor of his own.