Elon Musk has amended a lawsuit he brought this year against OpenAI, escalating his yearslong feud with the maker of the online chatbot ChatGPT.
The amended complaint, filed on Thursday in federal court in Northern California, makes new antitrust claims against OpenAI and adds defendants, including the tech giant Microsoft and the venture capitalist Reid Hoffman.
Microsoft is a close partner of OpenAI, after investing more than $13 billion in the start-up. Mr. Hoffman is a Microsoft board member and previously served on the board of OpenAI.
The new legal filing also adds two plaintiffs to the suit alongside Mr. Musk: his start-up xAI, which competes with OpenAI, and Shivon Zilis, a former OpenAI board member. Ms. Zilis is now an executive at Mr. Musk’s brain implant company Neuralink and the mother of three of his children.
“Elon’s third attempt in less than a year to reframe his claims is even more baseless and overreaching than the previous ones,” OpenAI’s spokesman, Jason Deutrom, said in a statement. Mr. Hoffman did not immediately respond to a request for comment. Microsoft declined to comment.