OpenAI’s board hired Emmett Shear, formerly of Twitch, as chief executive officer, defying calls from investors to reinstate the ousted Sam Altman, according to people familiar with the matter.

Shear had stepped down as CEO of Amazon.com Inc.’s game-streaming site Twitch earlier this year.

Members of the OpenAI board sought a CEO to succeed Altman in a stinging rebuke to investors, led by Microsoft Corp. and Thrive Capital, who have urged the board to step down and wanted Altman reinstated.

Board members of San Francisco-based OpenAI have reached out to at least two prominent executives in the technology industry in hopes one would take the role, the person said, asking not to be identified divulging private overtures.