TOKYO (Reuters) -SoftBank's Japanese telecoms unit will receive the first chips using Nvidia's latest Blackwell design for its supercomputer, the California-based chip designer said, as Masayoshi Son looks to ride the artificial intelligence boom.

SoftBank Corp is also planning to use Grace Blackwell chips for a further supercomputer, said Nvidia, which held an AI event in Tokyo on Wednesday featuring SoftBank Group CEO Son and Nvidia CEO Jensen Huang.

Son is pushing to expand his conglomerate's exposure to the AI wave, taking a stake in OpenAI and acquiring chip startup Graphcore, after a turbulent few years that forced the ebullient billionaire to retrench.

The two businessmen held a "fireside chat" at the event, with Jensen recalling Son had once offered to lend him money to buy Nvidia as its value was not understood by the market.

"He wanted to lend me money to buy Nvidia. All of it. Now I regret not taking it," Huang said, laughing.

Son said the offer was made a month after he acquired chip designer Arm. The Japanese billionare later built and sold down a stake in Nvidia and attempted the sale of Arm to Huang's company which foundered on regulatory hurdles.

Nvidia, once best known as a designer of graphic chips for gaming, has gone on to become the world's most valuable company powered by insatiable demand for its chips.

While Son has built a reputation as a far-sighted investor with relationships with leading entrepreneurs and bets on companies such as Alibaba, he has also made high profile slips such as backing office space sharing firm WeWork.

With telcos around the world look for new growth drivers, SoftBank has partnered with Nvidia to pilot a network that can run both 5G and AI services.

"It's the same vision that we can smell, right? It's like a wolf smell wolf," Son said of the similarities between the two men.

"I have two puppies. I don't like that mental image," Huang joked in response.

(Reporting by Anton Bridge; Writing by Sam Nussey; Editing by Neil Fullick, Muralikumar Anantharaman and Kim Coghill)