Sam Altman, the CEO of OpenAI, the company behind ChatGPT, has turned down a $97.4 billion (£78.4 billion) takeover offer from a group of investors led by Elon Musk.
Musk's attorney, Marc Toberoff, confirmed that he submitted the bid for "all assets" of the tech company to its board on Monday.
This offer is the latest development in an ongoing conflict between Musk, the world's richest man and close advisor to US President Donald Trump, and OpenAI CEO Sam Altman over the future of the start-up at the heart of the AI boom.
In response to the bid, Altman posted on Musk's social media platform X: "No thank you, but we will buy Twitter for $9.74 billion if you want."
His rejection of the bid doesn't necessarily mean the proposed takeover is off the table.
OpenAI's board will have a say in the company's future and might favor a sale, especially if the offer is increased.
However, there are also questions about how serious Musk is about actually acquiring the firm, and whether the offer is really part of the ongoing legal dispute between the two men.
Musk and Altman co-founded the start-up in 2015 as a non-profit company, but their relationship soured, and the Tesla and X boss left the firm in 2018.
Altman is reportedly restructuring the company to become a for-profit entity, removing its non-profit board—a move Musk argues means the company has abandoned its founding mission of developing AI for the benefit of humanity.
But OpenAI argues its transition into a for-profit firm is necessary to secure the funding needed to develop the best artificial intelligence models.
Christie Pitts, a tech investor in new businesses at Panasonic Well in San Francisco, told the BBC she was skeptical about Musk's motives.
"I think it's fair to be pretty suspicious of this considering that he has a competitor himself... which is structured as a for-profit company, so I think there's more than meets the eye here," she said.
The offer of $97.4 billion is much lower than OpenAI's valuation of $157 billion in its latest funding round last October. Talks about another funding round reportedly value it now at $300 billion.
In a statement, Mr. Toberoff said the group would be "prepared to consider matching or exceeding" any potential higher bid.
Musk's attorney added on behalf of Musk and other investors, "As the co-founder of OpenAI and the most innovative and successful tech industry leader in history, Musk is the person best positioned to protect and grow OpenAI's technology."
The creator of ChatGPT is also partnering with another US tech giant, Oracle, a Japanese investment firm, and an Emirati sovereign wealth fund to build $500 billion worth of artificial intelligence infrastructure in the US.
The new company, called The Stargate Project, was announced at the White House by President Donald Trump, who described it as "the largest AI infrastructure project by far in history" and said it would help keep "the future of technology" in the US.
Musk, despite being a top advisor to Trump, has claimed the venture does not "actually have the money" it has pledged to invest, though he has not provided any details or evidence for these comments.