China's "Big Four" State banks reported results for the first three quarters on Wednesday, with all showing a rise in soured assets.

Industrial and Commercial Bank of China Ltd had 87.36 billion yuan ($14.34 billion) in bad loans as of Sept 30, up 12.61 billion yuan from a year earlier.

Agricultural Bank of China Ltd's nonperforming loans stood at 87.9 billion yuan, up 3.97 billion yuan.

Bank of China Ltd reported 72.6 billion yuan in NPLs, up 7.96 billion yuan.

Bank of Communications Co Ltd's NPLs totaled 74.75 billion yuan, up 24.8 billion yuan.

"Banks are expected to accelerate writing off soured assets for the rest of the year," said Zhao Xijun, finance professor at Renmin University.

"NPLs are naturally rising as the economy slows. However, the overall asset quality of State-owned banks is stable."

The banks' profit growth rates are flattening, or in some cases declining, as the nation's GDP growth heads for 7.5 percent in 2013, the lowest level in recent years.

"The banks' growth rates are cooling down, along with the slowing down economy," said Zhao. "It will be the general trend for banks to lose momentum in profit gains."