South Korean bank's bad debt ratio stayed below one percent for two straight quarters amid still low borrowing costs, financial watchdog data showed Thursday.

Delinquent bank loan, overdue at least one month, stood at 0.97 percent of the total as of end-2018, after posting 0.96 percent three months earlier, according to the Financial Supervisory Service (FSS).

From a year earlier, the bad debt ratio declined 0.22 percentage points at the end of 2018.

It came amid the relatively low policy rate, which was raised to the current 1.75 percent in November last year. The country's central bank lifted its target rate from an all-time low of 1.25 percent to 1.50 percent in November 2017.

Delinquency ratio for corporate loans came in at 1.43 percent as of end-2018, down 0.33 percentage points from a year earlier.

The ratio for household loans inched down 0.01 percentage point to 0.23 percent in the cited period.