Nikkei rises 2.5 percent, Softbank jumps on Yahoo

(Updates to midsession)

TOKYO, Feb 4 (Reuters) - The Nikkei share average rose 2.5 percent on Monday, with Softbank Corp (9984.T: Quote, Profile, Research, Stock Buzz) jumping 13 percent after Microsoft's (MSFT.O: Quote, Profile, Research, Stock Buzz) $44.6 billion bid for Yahoo Inc.

Yahoo Japan Corp (4689.T: Quote, Profile, Research, Stock Buzz) was untraded due to a glut of buy orders.

Bank shares, including No. 1 Mitsubishi UFJ Financial Group (8306.T: Quote, Profile, Research, Stock Buzz), rose after news of a possible rescue plan for troubled U.S. bond insurers.

The benchmark Nikkei average .N225 ended the morning up 335.24 points at 13,832.40. The broader TOPIX index added 2 percent to 1,364.18. (Reporting by Taiga Uranaka)