In testimony on Tuesday before a nine-person jury in Oakland, California, federal court, the world’s richest person sharply criticised the 2019 decision by the nonprofit OpenAI co-founder and Chief Executive, Sam Altman and its ​President, Greg Brockman, to create a for-profit entity.

“If we make it okay to loot a charity, the entire foundation ​of charitable giving in America will be destroyed,” Musk testified.

OpenAI has said it created a for-profit ⁠entity to allow it to buy computing power and pay top scientists. Its lawyers have argued that Musk is motivated by ​a compulsion to control OpenAI and bolster his own AI company, SpaceX unit xAI, which lags OpenAI in user adoption.

Judge scolds Musk over X posts

The trial highlights the depth of the rupture between Musk and Altman. The two Silicon Valley icons once partnered in the quest to develop the fast-growing AI technology, a pillar of growth in the US economy that is also fuelling anxiety about job losses.

The pair co-founded OpenAI in ​2015 to create a benevolent steward of the technology and fend off rivals such as Alphabet Inc’s Google. Musk, the chief ​executive of Tesla and SpaceX, left OpenAI in 2018 after investing $38 million. Microsoft, also a defendant, invested $10 billion in OpenAI in 2023.

On Wednesday, Musk, ‌54, will ⁠resume being questioned by his own lawyer. He is then expected to be cross-examined by lawyers for OpenAI and the other defendants, who have argued that AI safety was not a priority for Musk when he was with the company and that he derided employees who focused on it as “jackasses.”

Before jurors were seated on Tuesday, US District Judge Yvonne Gonzalez Rogers admonished Musk after OpenAI ​lawyers complained about posts on ​X in which Musk assailed ⁠Altman as “Scam Altman.” Musk, known for brash public commentary, agreed to minimise his social media activity, as did Altman.

Musk seeks $150 billion in damages

The trial comes as OpenAI prepares for a potential initial ​public offering that could value it at $1 trillion, Reuters has reported. The company also faces ​growing competition from ⁠rivals, including Anthropic, while a Wall Street Journal report that OpenAI had missed some internal performance targets weighed on the tech-heavy Nasdaq Composite on Tuesday.

Musk is seeking $150 billion in damages from OpenAI and Microsoft, with any award going to OpenAI’s charitable arm. He also wants ⁠OpenAI to ​revert to a nonprofit, with Altman and Brockman removed as officers and Altman ​removed from the board.

His claims include breach of charitable trust and unjust enrichment.

OpenAI is currently structured as a public benefit corporation, in which the nonprofit and ​other investors, including Microsoft, hold stakes.