South Korean banks' net profit fell in the third quarter of the year from three months earlier on a fall in interest income, data showed Tuesday.

The combined net profit of 20 banks in the July-October period came to 6.2 trillion won ($4.44 billion), down 13.9 percent from three months earlier, according to the data from the Financial Supervisory Service.

From a year earlier, the reading marks a 14.8 percent rise.

The interest income of the 20 banks came to 14.6 trillion won in the third quarter, down 300 billion won from three months earlier.

The non-interest income of the 20 banks came to 2.3 billion won in the July-October period, up 800 billion won from three months earlier, according to the FSS.

The banks' return on assets ratio fell 0.12 percentage point to 0.65 percent over the cited period, while their return on equity ratio was also down 1.83 percentage points to 8.55 percent.

In the first nine months of the year, the banks' combined net profit also declined 3.4 percent to 18.8 trillion won, with their interest income up 0.6 percent to 44.4 trillion won. (Yonhap)