Thirteen banks that have released interim results saw slower growth with an increasing number of bad loans.

These banks earned 397.7 billion yuan ($64.9 billion) in net profits, a year-on-year increase of 14.2 percent, compared with an 18 percent growth rate during the same period of the previous year.

The rate was the slowest in four years.

Mid- and small-sized banks have performed better than large ones recently.

Banks' asset quality is facing increasing pressure as the economy slows down. NPL and its ratio have increased at most banks.

The NPL ratio of China CITIC Bank Co Ltd and the Industrial Bank Co Ltd rose more than 0.1 percentage points. Only China Construction Bank and Bank of Beijing have reported the same NPL ratio as that of the end of last year.