China Construction Bank, one of the country's top four lenders, said its net profit rose 14.1 percent year-on-year in 2012, lifted by growth in net interest income.

Net profit was 193.2 billion yuan ($31.2 billion) last year, rising from 169.3 billion yuan in 2011, the bank said in a statement over the weekend.

Net interest income -- calculated from interest earned less interest paid -- jumped 16.0 percent on-year to 353.2 billion yuan and accounted for more than two-thirds of the bank's operating income last year, it said.

But the bank warned China's gradual liberalisation of interest rates may hurt its profits in the future.

The central bank last year expanded the range that banks' deposit and lending rates can float around benchmark levels, a move which could result in narrower net interest margins for banks.

The bank said it will "actively conduct research on interest rate liberalisation" and "cultivate and improve its pricing capability" in response to the reform.

The bank's non-performing loan ratio dropped to 0.99 percent last year from 1.09 percent in 2011, according to the statement.

Its capital adequacy ratio, the measure of its capital to its assets, rose to 14.32 percent last year from 13.68 percent in 2011, helped by a 40 billion yuan bond issue, it said.

Shares of China Construction Bank were up 2.43 percent to HK$6.32 ($0.81) at midday in Hong Kong and up 1.49 percent to 4.78 yuan in Shanghai, where the company is also listed.