Sam Altman, the founder and CEO of OpenAI, has departed the company, its board of directors said Friday. OpenAI is behind the pioneering AI chatbot ChatGPT.

OpenAI's board wrote in a statement that Altman will step down as CEO and will be replaced temporarily by Chief Technology Officer Mira Murati.

The search for a permanent CEO continues, the statement read.

Altman's departure follows 'deliberate review process'

"Mr. Altman’s departure follows a deliberative review process by the board," the company said, "which concluded that he was not consistently candid in his communications with the board, hindering its ability to exercise its responsibilities."

Altman acknowledged he was leaving OpenAI in a post on X, formerly Twitter, but did not say anything about his interaction with the board.

"i loved my time at openai. it was transformative for me personally, and hopefully the world a little bit. most of all i loved working with such talented people. will have more to say about what’s next later," he wrote.

The board also said that OpenAI President Greg Brockman will be stepping down as chairman of the board but "will remain in his role at the company, reporting to the CEO."

The company said its board consists of OpenAI's chief scientist Ilya Sutskever, and three non-employees: Quora CEO Adam D'Angelo, tech entrepreneur Tasha McCauley, and Helen Toner of the Georgetown Center for Security and Emerging Technology.

Altman: a well-known face of AI

Altman helped start OpenAI as a nonprofit research laboratory in 2015 and his profile grew as the popularity of ChatGPT grew over the last few years.

He became a well-known face in the halls of government in debates over AI regulation and on a world tour earlier this year, he was mobbed by a crowd of adoring fans at an event in London.

OpenAI’s key business partner, Microsoft, which has invested billions of dollars into the startup and helped provide the computing power to run its AI systems, said the transition won’t affect its relationship.