Softbank says Sprint deal a risk but need to break out of Japan

The head of Japan's Softbank Corp said its decision to take a stake of up to 70 percent in U.S. carrier Sprint Nextel Corp in a $20.1 billion deal is a risk for the mobile carrier, but that it needs to break out of an ageing Japan.

"There is always a risk when you face a big challenge," Softbank founder and chief executive Masayoshi Son said at a news conference in Tokyo on Monday.

"We must enter a new market, one with a different culture, and we must start again from zero after all we have built. But not taking this challenge would have been a bigger risk."

(Reporting by Mari Saito; Writing by James Topham; Editing by Michael Watson)