Shinsei Bank is the most likely buyer of Daiichi Mutual Fire & Marine Insurance Co., which collapsed in May, industry sources said Thursday.

A foreign-capital nonlife insurance company has been named a likely buyer, but some of Daiichi Mutual's administrators believe the Shinsei Bank offer is best, the sources said.

Shinsei Bank and Daiichi Mutual are aiming to reach a basic agreement on the matter sometime this month, the sources said. Shinsei Bank, formerly Long-Term Credit Bank of Japan, intends to strengthen its management base by buying Daiichi Mutual, the sources said.

Daiichi Mutual's administrators, including the Marine and Fire Insurance Association of Japan, are looking for a buyer that will provide management stability in the future and reduce to the minimum the burden on policyholders that may be caused by a likely review of planned returns, according to the sources.

No bank has ever bought an insurance company in Japan. Basically, the law does not allow banks to enter the insurance sector, except when a bank takes over policies of a collapsed insurer.