OpenAI announced early Wednesday it reached an agreement with Altman to return to the company as CEO with a new initial board to be chaired by Bret Taylor, the former chair of Twitter, and also include Summers and Adam D'Angelo, the co-founder of Quora, a question-and-answer platform.

Summers, who served as a top economic adviser to former President Obama and as Treasury secretary under former President Clinton, already serves on multiple tech boards including digital payments company Block Inc and software company Skillsoft.

He was also named an adviser to venture capital firm Andreessen Horowitz in 2011, but he has not been publicly involved in recent investments, Bloomberg reported. Summers also served as Harvard's president in the early 2000s.

D'Angelo is the only returning member from OpenAI's previous board, which ousted Altman last Friday after a review found he "was not consistently candid in his communications with the board."

Altman's ousting prompted OpenAI co-founder and former president Greg Brockman to quit in protest, while hundreds of employees also reportedly threatened to quit unless Altman was brought back with a new board.

On Monday, Microsoft announced Altman and Brockman would be joining Microsoft to lead a "new advanced AI research team."

Brockman, however, confirmed Wednesday he would also be returning to OpenAI after the decision to bring back Altman. Microsoft CEO Satya Nadella said on X, the platform formerly known as Twitter, that the tech giant is "encouraged" by OpenAI's changes to the board and looks forward to continuing a partnership with the AI firm.