Mitsubishi UFJ Financial Group Inc., Japan's largest bank, would consider buying a commercial bank in the United States or Europe to expand its international operations, a senior executive said on Thursday.

The bank could buy a U.S. or European commercial lender in order to boost business outside of its mainstay domestic market, Norimichi Kanari, deputy president of Mitsubishi UFJ's core banking unit, told Reuters in an interview.

Foreign markets are becoming increasingly important for Japan's large banks, which face little potential for growth at home.

After cleaning up mountains of bad loans and repaying public debt, Japan's lenders are increasingly looking to make moves abroad.

Mitsubishi UFJ already has a presence in the United States through its unit UnionBanCal Corp., the parent of Union Bank of California.

The Japanese lender currently has operations in more than 40 countries.