Softbank Corp. announced on Tuesday that its group net profit tripled in the first half ended September due to a large increase of its mobile phone users.

The Japanese telecommunications and Internet service company earned a group net profit of 46.46 billion yen in the first half of its fiscal year, more than three times the14.44 billion yen in the first half last year. The first half revenue increased 22 percent to 1.365 trillion yen.

In the first half, Softbank Mobile cell phone business generated much profit for the company, which bought Vodafone Japan in April last year.

The number of contracts for the cell phone has increased to 17.05 million, up 1.75 million from the year before. Softbank did not show an earnings outlook for the fiscal year ending March 2008.

It was also separately announced that the company will book investment gains in the third quarter to December by the listing of Alibaba.com Ltd.

Softbank's financial results are based on Japanese accounting standards.