San Francisco, California - Hundreds of staff at OpenAI threatened to quit the leading artificial intelligence company on Monday and join Microsoft.

They would follow OpenAI co-founder Sam Altman, who said he was starting an AI subsidiary at Microsoft following his shock firing from the company whose ChatGPT chatbot has led the rapid rise of artificial intelligence technology.

In a letter, some of OpenAI's most senior staff members threatened to leave the company if the board did not get replaced.

"Your actions have made it obvious that you are incapable of overseeing OpenAI," said the letter, which was first released to Wired.

Included in the list of names of signers was Ilya Sutskever, the company's chief scientist and one of the members of the four-person board that voted to oust Altman.

It also included top executive Mira Murati, who was appointed to replace Altman as CEO when he was removed on Friday, but was herself demoted over the weekend.

"Microsoft has assured us that there are positions for all OpenAI employees at this new subsidiary should we choose to join," the letter said.

Reports said as many as 500 of OpenAI's 770 employees signed the letter.