A California jury has tossed out Elon Musk's high-profile lawsuit against OpenAI and its boss Sam Altman.

In a unanimous verdict, the jury agreed that Musk had waited too long to file his lawsuit, leaving all of his claims essentially expired.

Musk had accused Altman of breaching a non-profit contract by shifting the ChatGPT-maker to a for-profit company after Musk donated $38m early in OpenAI's history.

Musk claimed Altman had deceived him by accepting his money and then reneging on OpenAI's original non-profit mission to develop artificial intelligence (AI) technology for the benefit of humanity.

Jurors spent just about two hours on Monday deliberating on the case, but they had spent three weeks viewing internal correspondence and hearing testimony from Musk, Altman, and other tech industry executives, such as Microsoft's chief executive Satya Nadella.

Musk had accused Microsoft of aiding and abetting OpenAI in its allegedly improper transition to a more for-profit company.

Musk's other claims against Microsoft were dismissed as a matter of law given the jury's findings on the two claims against OpenAI.

A spokesperson for Microsoft said of the verdict: The facts and the timeline in this case have long been clear.

The jury's decision adds to a string of recent losses and settlements for Musk in court.

Within a few hours of the verdict, Musk criticized the decision against him in the OpenAI case, writing on X that it created a free license to loot charities if you can keep the looting quiet for a few years!

He also accused the judge overseeing the case of being a terrible activist who used the jury as a fig leaf.

As the jury found that the statute of limitations for Musk's claims had lapsed, they were not required to consider the merits of his claims. Law professor Carl Tobias said the jurors had made a very fact-based decision about the case.

On the trial's first day, Musk took the stand wearing a dark suit and tie, insisting, It's actually very simple. It's not OK to steal a charity... If it's okay to loot a charity, the entire foundation of charitable giving will be destroyed.

Altman testified that Musk had originally backed the shift toward a for-profit model. The lawsuit embodied a building animosity between the two since Musk's departure from OpenAI in 2018, after being denied control.

This ruling is seen as both a win for OpenAI and a potential warning to other entities regarding the importance of timely legal actions.