The shenanigans at OpenAI have continued overnight, with Sam Altman returning as CEO, which means interim CEO and former Twitch boss Emmett Shear lasted just two days.

In a tweet announcing Altman’s rehiring, OpenAI said: “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.”

Altman, who was sacked on Friday and subsequently offered a lucrative job to head up Microsoft’s Advanced AI business on Sunday evening, tweeted: “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. When I decided to join Microsoft on Sunday evening, it was clear that was the best path for me and the team with the new board and with Satya’s [Nadella, Microsoft CEO] support. I’m looking forward to returning to OpenAI, and building on our strong partnership with Microsoft.

The news comes after pretty much all members of staff at OpenAI threatened to leave the company if Altman was not rehired. The reason for Altman’s dismissal has not yet been disclosed, but what is clear from some industry watchers is that the drive to create a profitable business that is a high motivation among investors is at odds with the not-for-profit charter of OpenAI, which employees have signed up to.

On Tuesday, OpenAI co-founder and chief scientist Ilya Sutskever tweeted: “I deeply regret my participation in the board’s actions. I never intended to harm OpenAI. I love everything we’ve built together and I will do everything I can to reunite the company.”

This has led to Altman returning to OpenAI, which potentially scuppers Microsoft’s plans to have him head up the company’s new Advanced AI division. The turmoil at OpenAI over the past few days would have potentially led to highly talented and much sought-after AI experts abandoning OpenAI to join their former boss, with Microsoft reportedly offering to match their salaries. Other industry chief executives, like Marc Benioff of Salesforce, are also believed to have been trying to entice OpenAI’s workforce.

In a tweet, Nadella said: “We are encouraged by the changes to the OpenAI board. We believe this is a first essential step on a path to more stable, well-informed and effective governance. Sam, Greg and I have talked and agreed they have a key role to play along with the OAI [OpenAI] leadership team in ensuring OAI continues to thrive and build on its mission. We look forward to building on our strong partnership and delivering the value of this next generation of AI to our customers and partners.”