South Korean banks saw their first-quarter earnings decline 17.8 percent from a year earlier due to increased loan-loss provisions, data showed Wednesday. 

The combined net profit stood at 3.2 trillion won ($2.6 billion) for the January-March period, compared with a profit of 4 trillion won a year earlier, the Financial Supervisory Service said in a statement. 

Preliminary interest income for the first quarter stood at 10.1 trillion won, down 0.2 percent from a year earlier. 

Loan-loss provisions jumped 42.5 percent on-year to 1 trillion won, the FSS said.

The average net interest margin of the banks, a key barometer of profitability, stood at 1.46 percent for the first quarter, down 0.15 percentage point from a year ago. (Yonhap)