Elon Musk says he will abandon his $97.4bn offer to buy the non-profit behind OpenAI if the ChatGPT maker drops its plan to convert into a for-profit company.

“If OpenAI, Inc.’s Board is prepared to preserve the charity’s mission and stipulate to take the ‘for sale’ sign off its assets by halting its conversion, Musk will withdraw the bid,” lawyers for the billionaire said in a filing to a California court on Wednesday. “Otherwise, the charity must be compensated by what an arms-length buyer will pay for its assets.”

Musk and a group of investors made their offer earlier this week, in the latest twist to a dispute with the artificial intelligence company that he helped found a decade ago.

OpenAI is controlled by a non-profit board bound to its original mission of safely building better-than-human AI for public benefit. Now a fast-growing business, it revealed plans last year to formally change its corporate structure.

Musk and his own AI startup, xAI, and a consortium of investment firms want to acquire the non-profit’s controlling stake in the for-profit OpenAI subsidiary.

OpenAI’s CEO, Sam Altman, quickly rejected the unsolicited bid in a post on social media and told questioners at a Paris summit on AI that the company is not for sale. The chair of OpenAI’s board, Bret Taylor, echoed those remarks at an event on Wednesday.

Musk and Altman helped start OpenAI in 2015 and later competed over who should lead it before Musk resigned from the board in 2018. They’ve been in a long-running and bitter feud over the startup, with Musk suing, dropping his suit, and then suing again in 2024.

Musk again criticized Altman’s management on Thursday during a videocall to the World Governments Summit in Dubai, United Arab Emirates, describing it as akin to a nonprofit aimed at saving the Amazon rainforest becoming a “lumber company that chops down the trees”. Altman has repeatedly countered that Musk’s legal challenges to OpenAI are motivated by his role as the founder of a competing startup.

Musk has asked a California federal judge to block OpenAI’s for-profit conversion on allegations ranging from breach of contract to antitrust violations. The judge has expressed skepticism about some of Musk’s arguments but hasn’t yet issued a ruling.