Mira Murati, OpenAI’s chief technology officer, is one of several employees leaving the company, triggering a leadership shake-up at the AI start-up as it discusses changing its corporate structure.

In a message shared with employees on Wednesday, Murati said: “After much reflection, I have made the difficult decision to leave OpenAI.” Bob McGrew, chief research officer, and Barret Zoph, vice-president of research, also said on Wednesday that they were leaving the company.

It is the latest blow to the Microsoft-backed artificial intelligence start-up, which has had several high-profile departures this year, including founders John Schulman and Ilya Sutskever. Schulman has joined rival Anthropic, while Sutskever has launched his own venture aimed at building “safe” AI models.

Only two of OpenAI’s 11 founders remain, after Greg Brockman in August announced he would be taking a leave of absence until the end of the year.

Murati, 35, has led the company’s efforts to build ChatGPT as a standalone product, building on the technical breakthroughs made with GPT, the large language model that underpins it. She also oversaw releases and improvements of the company’s image generator Dall-E and AI code generator Codex after joining OpenAI in 2018.

Sam Altman, OpenAI’s chief executive, named a new senior vice-president of research, Mark Chen, and a new head of mission alignment, Josh Achiam, promoted from research scientist to make sure “we get all pieces (and culture) right to be in a place to succeed at the mission”.

“Leadership changes are a natural part of companies, especially companies that grow so quickly and are so demanding,” Altman added. “I obviously won’t pretend it’s natural for this one to be so abrupt, but we are not a normal company”.

“Mira, Bob, and Barret made these decisions independently of each other and amicably, but 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,” he added in a post on X.

Last November, Murati was made interim CEO after OpenAI’s board ousted Altman for what it said was his failure to be candid. Murati was in the position for four days until Altman returned, following intense pressure from investors and staff. He was later cleared to rejoin the board following an independent review into his conduct.

Murati’s departure is a reminder of lingering scars that incident left at the rapidly growing San Francisco start-up, which was founded as a non-profit dedicated to ensuring that artificial general intelligence — which aims to replicate human intelligence — would benefit all of humanity. In 2019, it changed its structure to include a capped-profit enterprise, allowing it to raise large amounts of capital from the likes of Microsoft, which has invested $13bn.

The ChatGPT maker is now one of Silicon Valley’s most valuable companies and is raising more than $6bn at a $150bn valuation, said multiple people familiar with the matter.

At the same time, it is in discussions to change its corporate structure to become more investor-friendly and has released new products, including new AI models such as o1, which it says are capable of reasoning, and additional voice capabilities.

“We remain focused on building AI that benefits everyone and as we’ve previously shared we’re working with our board to ensure that we’re best positioned to succeed in our mission. The non-profit is core to our mission and will continue to exist,” said OpenAI.

Murati wrote on Wednesday that she was leaving because she wished to “create the time and space to do my own exploration”. She added her primary focus would be to “ensure a smooth transition”.

“While I may no longer be in the trenches with you, I will still be rooting for you all,” she wrote.

In October, a month before last year’s leadership turmoil, Sutskever and Murati were two of the senior executives who brought concerns about Altman to the board, said three people close to the matter. Their concerns included Altman’s leadership style, which they felt undermined and pitted people against one another, one of the people said. Murati and others believed his actions created a toxic environment and fed into the board’s decision to fire him, and the means by which they did so, they added.

Within a day of Altman’s firing, however, Sutskever and Murati were negotiating for Altman’s return, and both stayed at OpenAI after his reinstatement as chief executive. As the start-up tried to recover from the instability, a rift developed over the commercialisation of the company and a pressure to develop products that it could monetise, said former and current employees.

“As a whole the company has definitely become more of a normal tech company over time, more product-oriented and winning-oriented and less altruistic,” said a former employee.

“The core researchers are still loyal to Sam personally and are in it because they want to build [artificial general intelligence], not because they want to make money.”

In March, Murati said it was “disheartening to witness the previous board’s efforts to scapegoat me with anonymous and misleading claims in a last-ditch effort to save face in the media”, telling staff she had a “strong and productive relationship” with Altman and was “not shy” in her feedback to him.

Murati and Sutskever declined to comment.

Additional reporting by George Hammond