OpenAI gets new $1.5 billion investment from SoftBank, allowing employees to sell shares in a tender offer

OpenAI is allowing employees to sell roughly $1.5 billion worth of shares in a new tender offer to SoftBank, CNBC has learned.

The new financing will allow the Japanese tech conglomerate to get an even larger slice of the AI startup, and it will allow current and former OpenAI employees to cash out their shares, two people familiar with the matter told CNBC.

Employees will have until Dec. 24 to decide if they want to participate in the new tender offer, which has not previously been reported, one of the people said. The deal was spurred by SoftBank billionaire founder and CEO Masayoshi Son, who was persistent in asking for a larger stake in the startup after putting $500 million into OpenAI's last funding round, one of the people said.

The tender offer is not related to OpenAI's potential plans to restructure the firm to a for-profit business, one of the people said.

OpenAI and SoftBank declined to comment.

The news underscores Son's interest in the AI space and in backing the most valuable private players. SoftBank was an early investor in Arm, and Son said at a recent conference that he's saving "tens of billions of dollars" to make the "next big move" in artificial intelligence. He had previously invested in Apple, Qualcomm and Alibaba.

SoftBank's Vision Fund 2 recently invested in AI startups Glean, Perplexity and Poolside. SoftBank has about 470 portfolio companies and $160 billion in assets across its two vision funds.

The OpenAI investment matches SoftBank's eagerness to deploy cash, with a capital-intensive business model, a person close to Son told CNBC.

Even without SoftBank's deep pockets, OpenAI has had no trouble raising billions in cash. Its valuation has climbed to $157 billion in the two years since launching