The offer from Morgan Stanley was unsolicited and came with many others, the statement says. The sale of the building is hoped to improve the bank's bottom line, which was hit by the problems in the US mortgage market, and management is increasing the bank's profit forecast as a result of the sale by 15 million yen, to 65 million yen, for the fiscal year ending March 31.

"This simply makes good economic sense," says Thierry Porté, president and CEO of Shinsei Bank. "It's an opportunity to realign our front- and back-office operations, invest in Japanese assets and better position ourselves to build greater shareholder value going forward."

The Shinsei headquarters was built in 1993, and the company's statement says it has a book value of 53 million yen. Shinsei has total assets of about $104 billion and 42 banking outlets in Japan.