Bret Taylor, the chairman of OpenAI’s board, said the artificial intelligence company was “not for sale.” Mr. Musk and other investors had offered $97.4 billion earlier this week.

OpenAI attorney William Savitt said the proposal "is not in the best interests of OAI's mission and is rejected."

Elon Musk's AI company, xAI, is said to be in talks to raise $10 billion in a round that would value xAI at $75 billion.