Sumitomo Trust & Banking Co. has agreed to pay ¥120 billion for Citigroup Inc.'s Japanese asset management unit to increase the amount of investment trusts it oversees.

Sumitomo Trust will buy Nikko Asset Management Co. in October, the Osaka-based lender said Thursday. The company will sell ¥109 billion in preferred securities in September to bolster capital, it said in a separate release.

The credit crisis has given Japanese companies an opportunity to take market share. Citigroup has sold units, Morgan Stanley agreed to put its Japanese securities arm into a venture with Mitsubishi UFJ Financial Group Inc., and Nomura Holdings Inc. bought Lehman Brothers Holdings Inc.'s Asia business.