"The timing of Mira's decision was such that it made sense to now do this all at once, so that we can work together for a smooth handover to the next generation of leadership," Altman wrote.

They're the latest high-level executive to depart OpenAI, which has exploded in popularity and value since releasing the ChatGPT chatbot in late 2022. OpenAI co-founder Ilya Sutskever and former safety leader Jan Leike announced their departures in May. Co-founder John Schulman said last month that he was leaving to join rival Anthropic.