Hong Kong (CNN Business) SoftBank is raising $23.5 billion from the IPO of its Japanese mobile business, making it the second biggest stock market listing ever.

Strong demand from investors for a piece of one of Japan's biggest wireless carriers prompted the Japanese tech company to increase the number of shares available by 160 million.

It priced the shares at 1,500 yen ($13) each, raising a total of 2.65 trillion yen ($23.5 billion), it said in a statement Monday.

That makes it Japan's biggest ever IPO — and the world's largest since Alibaba ( BABA ) raised $25 billion when it went public in New York in 2014, according to data from Dealogic.

Listing the mobile business is a key part of CEO Masa Son's efforts to reposition SoftBank ( SFTBY ) as a global tech investor. The transaction splits the company in two, allowing investors to choose between its mobile unit and its tech investment business, which includes a big stake in Alibaba.

Son has become a major player in the global tech industry after launching the almost $100 billion Vision Fund last year. Nearly half the money came from the Saudi government.

The Vision Fund has plowed cash into dozens of startups like WeWork and Slack.

SoftBank has also made big investments in high-profile tech companies like Uber and its Chinese rival, Didi Chuxing.

Selling shares in the mobile division will raise billions of dollars for Son to hunt down more major deals.

Shares in the mobile unit begin trading in Tokyo on December 19.