Ousted OpenAI chief Sam Altman is poised to return to run the company he co-founded under the supervision of a new board, following days of speculation and turmoil at the leading generative artificial intelligence start-up.

In a dramatic reversal, Altman, who was fired by OpenAI’s board of directors last week, will return to the helm of the high-profile AI start-up, the company said late on Tuesday in California. Greg Brockman, the co-founder who quit the company after Altman was fired, will return alongside him. Brockman was president of the company until he quit on Friday but did not say what role he would take up on his return.

Under an “agreement in principle”, Altman will serve under the supervision of a new board of directors, consisting initially of former Salesforce chief executive Bret Taylor as chair, former US Treasury secretary Larry Summers and Adam D’Angelo, an existing OpenAI board member and the chief executive of question-and-answer platform Quora.