Standard & Poor's Ratings Service said Thursday it expects to assign on Jan. 3 a long-term counterparty credit rating of A to Bank of Tokyo-Mitsubishi UFJ, a new bank that will form Jan. 1 through the merger of BTM and UFJ Bank.

The outlook for the long-term rating is expected to be stable and the new bank's short-term counterparty rating will be A-1, the U.S. credit rating agency said.

Bank of Tokyo-Mitsubishi UFJ will be one of the largest commercial banks in the country in terms of total assets and loan balances, and will serve as the core unit of Mitsubishi UFJ Financial Group Inc., it said.

The group was formed through the Oct. 1 merger of Mitsubishi Tokyo Financial Group Inc. and UFJ Holdings Inc.