OpenAI says its board of directors has unanimously rejected a $97.4 billion takeover bid by Elon Musk.

“OpenAI is not for sale, and the board has unanimously rejected Mr. Musk’s latest attempt to disrupt his competition,” said a statement Friday from Bret Taylor, chair of OpenAI’s board.

OpenAI attorney William Savitt in a letter to Musk’s attorney Friday said the proposal “is not in the best interests of OAI’s mission and is rejected.”

Musk, an early OpenAI investor, began a legal offensive against the ChatGPT maker nearly a year ago, suing for breach of contract over what he said was the betrayal of its founding aims as a nonprofit.

OpenAI has increasingly sought to capitalize on the commercial success of generative AI. But the for-profit company is a subsidiary of a nonprofit entity that’s bound to a mission — which Musk helped set — to safely build better-than-human AI for humanity’s benefit. OpenAI is now seeking to more fully convert itself to a for-profit company, but would first have to buy out the nonprofit’s assets.