(Reuters) - John Schulman, one of the co-founders of artificial intelligence company OpenAI, has left the ChatGPT maker for rival Anthropic, he said in a post on social media platform X late Monday.

"This choice stems from my desire to deepen my focus on AI alignment, and to start a new chapter of my career where I can return to hands-on technical work," Schulman said in his X post.

OpenAI's President and co-founder Greg Brockman is also taking a sabbatical through the end of the year, he said in a X post late Monday.

The news was first reported by The Information, which added that Peter Deng, a product manager who joined OpenAI last year, has also exited the company.

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

The move comes as OpenAI faces significant personnel changes, with the company's AI safety leader Aleksander Madry being reassigned to another role in July.

Another one of OpenAI's co-founders and chief scientist, Ilya Sutskever, left the company in May. Andrej Karpathy, who was also one of the AI firm's founding members left OpenAI in February and started an AI-integrated education platform in July.

Tesla CEO Elon Musk, who was also one of the co-founders of OpenAI and left three years later, revived his lawsuit against the company and CEO Sam Altman on Monday, saying that the firm put profits and commercial interests ahead of public good.