Softbank Corp. has reached an agreement to buy the Japan unit of British mobile phone company Vodafone for 1.75 trillion yen, or $15 billion

With the deal struck on Friday, Softbank will acquire the entire 97.7 percent stake of Vodafone Group PLC's struggling Japan unit along with its 15 million subscribers, propelling the Internet services company into the No. 3 position among Japanese cell phone providers after NTT DoCoMo and KDDI Corp.

Softbank announced that it will initiate new Third Generation (3G) digital mobile services which will include news broadcasting, online auctions and chat services in addition to the established broadband services it already provides.

The combined revenue of Sofbank and the Vodafone unit will be 2.5 trillion yen per year, about the same as its closest competitor, the KDDI group.

The buyout will be carried out by one of Softbanks wholly-owned subsidiaries, BB Mobile Corp. by borrowing from 1.1 to 1.2 trillion yen from banks. Softbank will invest 200 billion yen and its affiliate Yahoo Japan Corp. will invest 120 billion yen for the acquisition.