Sam Altman, who co-founded OpenAI, the influential maker of ChatGPT, will join Microsoft to help lead a new advanced artificial intelligence team.

The surprise development follows Altman's abrupt ouster from OpenAI by its board of directors over an apparent rift over balancing AI safety with the push to publicly release new powerful AI tools into the world.

Microsoft CEO Satya Nadella made the announcement that Altman, 38, would be coming on board in a post on X sent just before 3 a.m. eastern time Monday.

Nadella also said Greg Brockman, the former president of OpenAI who quit in protest after Altman's sudden departure, would be joining the new AI division at Microsoft alongside Altman.

"We look forward to moving quickly to provide them with the resources needed for their success," Nadella said.

The board pushing out Altman threw OpenAI into turmoil. Microsoft has invested $13 billion into OpenAI, which is said to have been working on a deal that would value the company at nearly $90 billion, but that is now in limbo in the wake of Altman's exit.

OpenAI, founded by Altman, Elon Musk and others about eight years ago as a nonprofit AI research lab, released ChatGPT last year, setting the pace for the entire tech industry's focus on a sophisticated type of artificial intelligence known as generative AI.

But fissures started to form when some members of the board became concerned that Altman wanted to rapidly push out AI products into the world and feverishly sign up customers without fully reckoning with the risks. Some critics of OpenAI have argued that the company abandoned its nonprofit ethos by re-organizing as a quasi-profit-driven company and taking major investment funding from Microsoft and others.

Separately, OpenAI's board announced it has hired former Twitch CEO Emmett Shear to lead the company, naming him the interim CEO despite calls from some OpenAI investors to bring back Altman.

Shear, who stepped down from Amazon's Twitch last year, has been vocal about the potential societal dangers of advanced AI.