06:14 AM EST, 11/27/2024 (MT Newswires) -- Microsoft ( MSFT ) -backed OpenAI is allowing its employees sell $1.5 billion of stock in a new tender offer to Japan's SoftBank Group, multiple news outlets reported Wednesday.

The artificial intelligence start-up raised $500 million from the Japanese conglomerate in a $6.6 billion funding round in October at a valuation of $157 billion, the reports said.

OpenAI employees have until Dec. 24 to decide whether they they want to participate in the new funding round, and the stock's offer price is consistent with the company's previous funding round, the reports said.

SoftBank and OpenAI did not immediately respond to MT Newswires' request for comment.