SAN FRANCISCO, United States (AFP) — Jensen Huang resigned as chief executive of AI giant Nvidia on Thursday after revelations he had two extramarital affairs, including one with a woman accused of spying for China.

Chief financial officer Colette Kress will serve as interim chief executive officer while the board searches for a permanent successor, the company said, ending Huang’s 33-year run at the helm of the global juggernaut he co-founded.

Huang, 63, also gave up his seat on the board. The company did not give a reason for his departure.

The scandal has sent shares of the multi-trillion-dollar company plunging, and the exit of Huang, who has been a key promoter of the artificial intelligence boom, leaves Nvidia without its leather-jacket-clad leader at a crucial time for the sector.

Huang was a central figure in the revolution set off by the launch of OpenAI’s ChatGPT in 2022, with Nvidia’s powerful processors, once intended for video game graphics, becoming the crucial ingredient for building the AI models now spreading across the world.

At the heart of the spy allegations is the race between the United States and China, with both superpowers trying to get ahead in an industry widely seen as the next industrial revolution.

Nvidia shares were down as much as 13 per cent in early trading on Wall Street following the announcement, with US$800 billion wiped off the company’s valuation since the weekend.

Analyst Dan Ives of Yorkville Ives called it “a dark day for Nvidia and the US tech industry”, but said the board had done what it needed to: “rip off the band-aid and take Nvidia into its next chapter without him”.

The board said it had appointed Harvey Jones, a former chief executive of chip design software firm Synopsys, as chair.

“The board has full confidence in Colette and the leadership team, and we expect the company’s operations, customer commitments and product roadmap to continue without interruption,” Jones said in a statement.

Kress said she was committed to “building on the extraordinary foundation Jensen created over the last 33 years”.

The scandal began with reports that Huang, who has been married to Lori Huang for more than 40 years, was involved in an extramarital relationship.

Jensen Huang admitted on Sunday to having an affair, reportedly with Alice Huang, who was a senior executive at Singapore-based data centre company Megaspeed. The two are not related.

US intelligence reportedly circulated a memo this spring alleging Alice Huang was an asset of China’s Ministry of State Security.

Beijing has rejected the spying allegations.

On Sunday, Nvidia’s board announced a probe into what it called reporting that Huang had been the target of a “foreign intelligence effort”, while saying it retained confidence in him.

However, on Wednesday, The New York Times reported that Huang had a second extramarital affair, citing video evidence of him being affectionate with Nvidia’s vice president of health care, Kimberly Powell.

Powell, 48, has been a public face of Nvidia’s efforts to expand its technology into higher education and health care. She was speaking at a conference in San Jose, California, where the two “were seen being affectionate at the hotel” by bystanders, the Times reported.

Nvidia’s code of conduct tells employees to avoid conflicts of interest and cites the example of “personal relationships”.

Nvidia shareholders have filed a class action lawsuit against Huang and the company for failing to disclose information about the relationship to investors.

Huang had repeatedly avoided naming a successor when the question was raised.

Kress joined Nvidia as finance chief in 2013 after nearly 25 years in financial roles at companies including Cisco and Microsoft.

Nvidia’s processors are mostly made by Taiwanese company TSMC, the world’s largest contract manufacturer of chips.

Nvidia said it would release its quarterly results as scheduled on November 17.

In response to a post on social media asking him to hire Huang after his Nvidia exit, SpaceX boss Elon Musk said it would be “honour” to do so.