BEIJING, Jan. 23 -- The non-performing loan ratio of China's commercial banks rose to 1.29 percent in the fourth quarter last year, a level not seen since the second quarter of 2010, official data showed on Friday.

The ratio was up from 1.16 percent at the end of September, the China Banking Regulatory Commission (CBRC) said. Commercial banks' bad debt ratio stood at 1.3 percent in the second quarter of 2010.

Data released this week showed China's economic growth slowed to a 24-year low of 7.4 percent in 2014 as a property downturn and industrial overcapacity weighed on investment and activity.

Despite the rise in the bad debt ratio, Wang Zhaoxing, vice chairman of the CBRC, said the risk in China's banking sector is "under control" with the banks' capital adequacy ratio and provision coverage ratio both at high levels.

By the end of November, banks' capital adequacy ratio, which reflects a bank's capacity to cushion potential losses with its capital, stood at 12.93 percent, up 0.75 percentage point from one year earlier. However, CBRC did not say what the figure was as of the end of December.