OpenAI's staff has threatened to quit the artificial intelligence startup and join former boss Sam Altman at Microsoft's new division unless the board resigns, according to a letter seen by Reuters.

Apart from Chief Technology Officer Mira Murati, Chief Data Scientist Ilya Sutskever and Chief Operating Officer Brad Lightcap, about 500 members of OpenAI staff said they would resign, a person familiar with the matter told Reuters.

OpenAI did not immediately respond to a Reuters request for comment.

(Reporting by Akash Sriram in Bengaluru; Editing by Shweta Agarwal and Anil D'Silva)