SoftBank Group's second-quarter operating profit rose 39 percent on cost cuts and some improvement at its struggling U.S. unit Sprint Corp. SoftBank, which purchased a majority stake in U.S. wireless carrier Sprint for more than $20 billion in 2013, said on Wednesday its July-September operating profit climbed to 342 billion yen from 246 billion a year earlier. That beat an average estimate of 329 billion yen from four analysts, according to Thomson Reuters, and the company said the main reasons for the strong results included higher profits from segments such as Sprint.