Shinsei Bank Ltd., the Japanese lender partly owned by investor Christopher Flowers, plans to sell preferred securities to boost its capital.

The amount to be sold has not been decided, the Tokyo-based bank said in a statement Friday. Shinsei plans to issue the securities this month.

The lender said Feb. 3 it expects to post a net loss of ¥48 billion for the full year ending March 31, as it takes losses on overseas investments and loans to bankrupt Lehman Brothers Holdings Inc.

The Tokyo-based bank's Tier 1 capital ratio, a key indicator of financial strength, was the lowest of eight nationwide lenders at 6.64 percent as of Dec. 31, according to Bloomberg data.

Shinsei joins larger banks, including Mitsubishi UFJ Financial Group Inc. and Mizuho Financial Group Inc., in raising capital as losses on investments sap their financial strength.

Shinsei has fallen 81 percent in Tokyo trading in the past 12 months, the most among 84 lenders in the Topix Banks Index, as it faces the second loss in three years.

Masamoto Yashiro, 80, became Shinsei's chief executive officer in November, when Thierry Porte stepped down from the job to take responsibility for mounting losses.