The bank currently trades at 0.9 times its estimated net asset value, 10 percent lower than the average for the industry, and KBW's pricing model suggests the shares could gain as much as 27 percent, said its Hong Kong-based analyst Bill Stacey, in a note raising the Beijing-based lender's rating from "market perform".

Bank of China got about a fifth of its 2011 net revenue from overseas, more than any of its larger rivals, according to recent data compiled by Bloomberg.

The lender is the only Chinese bank included on the Financial Stability Board's provisional list of 29 systemically important financial institutions.

China Daily-Agencies