Tokio Marine Holdings Inc., the nation's second-largest nonlife insurer, is seeking to expand in Southeast Asia as Japan's shrinking population erodes its domestic market.

The insurer plans to expand in life insurance, automobile coverage, reinsurance and asset management, President Tsuyoshi Nagano said. The Tokyo-based company will increase its presence both organically and through possible takeovers, he said, declining to elaborate.

Japanese insurers are being lured by the region's growth potential as they grapple with an aging society and shrinking population at home. Tokio Marine is expecting premium income from casualty and life insurance businesses in Asia to increase 19 percent and 9.2 percent, respectively, this business year, according to its business plan released in May.