The move is part of a drive by Japan's second-largest lender to capture growth in Asian emerging markets through acquisitions, spurred on by limited business opportunities at home with ultra-low interest rates and an aging population.

The investment would raise Sumitomo Mitsui's stake in RCBC to 20%. Last year, it took a 5% stake in RCBC, the No. 6 non-state bank in the Philippines.

Sumitomo Mitsui hopes to leverage RCBC's branch network in the Philippines to better support its Japanese customers seeking to expand in the country, it said in a statement.

The investment is also designed to boost RCBC's capital base, it added.

Sumitomo Mitsui announced a raft of deals in Asia in recent years, including a $2 billion acquisition of an Indian non-bank lender and an investment in Vietnam's biggest non-bank lender.

In the United States, another area of focus for Sumitomo Mitsui, the lender struck a capital alliance with Jefferies Financial Group Inc.

(Reporting by Makiko Yamazaki; editing by Jason Neely)