TOKYO (AP) — SoftBank Group Corp.'s Japanese mobile subsidiary has begun trading in one of the world's biggest share offerings rivaling that of China's Alibaba Group.

Wednesday's IPO on the Tokyo Stock Exchange seeks to raise more than 2 trillion yen ($18 billion).

Softbank fetched the initial price of 1,463 yen ($13.03), down 2 percent from the IPO price of 1,500 yen announced earlier this month.

Softbank is listing 1.6 shares, or about one third held by its parent company.