Sam Altman is to return as chief executive of OpenAI after the ChatGPT developer said it had “reached an agreement in principle” for his reinstatement.

The San Francisco-based company made the announcement after days of corporate drama in the wake of Altman’s surprise sacking on Friday. Nearly all of OpenAI’s 750-strong workforce had threatened to quit unless the board overseeing the business brought back Altman and then quit immediately afterwards.

As part of the agreement reached overnight, the deal includes a new-look board led by Bret Taylor, the former co-CEO of software firm Salesforce. It will include Larry Summers, the former US treasury secretary, and Adam D’Angelo, the tech entrepreneur and current board member who played a role in Altman’s firing.

“We have reached an agreement in principle for Sam Altman to return to OpenAI as CEO with a new initial board of Bret Taylor (Chair), Larry Summers, and Adam D’Angelo. We are collaborating to figure out the details. Thank you so much for your patience through this,” wrote OpenAI on its official account on X, formerly known as Twitter.

Altman posted soon after: “I love OpenAI, and everything I’ve done over the past few days has been in service of keeping this team and its mission together.” He added: “I’m looking forward to returning to OpenAI.”

Altman was fired on Friday by the the board of OpenAI’s non-profit parent, which oversees a commercial subsidiary run by the 38-year-old. He had reportedly made the removal of the board, and an overhaul of OpenAI’s governance, a precondition of his return.

Microsoft, OpenAI’s biggest investor, has been pushing for Altman’s reinstatement. On Monday it hired Altman and OpenAI’s president, Greg Brockman, who quit on Friday after his colleague’s sacking, in a move interpreted by analysts as giving the ex-CEO a de facto leadership role over his former employer. Brockman also confirmed on X that he was returning to OpenAI, tweeting “we are so back” in a selfie with colleagues.