SHANGHAI -- Firms listed on the Shanghai and Shenzhen stock exchanges saw double-digit revenue and profit growth in the first nine months of the year, boosted by a resilient economy.

By the end of October, 1,368 firms had published their quarterly reports, with nearly 60 percent posting revenue and profit growth, the Shanghai exchange said on Wednesday.

Statistics showed that the combined revenue reached 20.67 trillion yuan ($3.1 trillion) in the January-September period, up 17.7 percent year-on-year, the exchange said.

Meanwhile, combined profits totaled 2.04 trillion yuan, up 16.7 percent year-on-year.

China's supply-side structural reform has improved the earnings of traditional companies, while firms from many new industries reported robust growth, a sign of improved economic growth, the bourse said.

Non-financial companies reported a combined revenue of 16.08 trillion yuan, up 21.3 percent year-on-year. Their net earnings rose 39.5 percent to 760 billion yuan.

During the period, China's four biggest State-owned banks saw non-performing loan ratios down by 0.02 to 0.4 percentage points from the end of last year.

Meanwhile, the four leading insurance companies, namely China Life, Ping An Insurance, China Taiping and New China Insurance, saw net profits rise 30 percent year-on-year to 109.1 billion yuan.

In the first three quarters, more than 180 new firms were listed on the Shanghai stock exchange. They posted 17.7 percent growth in revenue and 28.1 percent growth in net profits.

A total of 2,051 companies have published their quarterly reports, the Shenzhen bourse said on Wednesday. Earnings and net profits have both posted double-digit growth in industries such as manufacturing, construction and transportation.

Net profits of the manufacturing industry grew by 41.87 percent year-on-year, it said. ' By the end of October, 919 listed firms on the Shenzhen exchange published their yearly forecasts. About 80 percent of them expect positive growth for the whole year, the exchange said.

China's benchmark Shanghai Composite Index closed 0.08 percent higher at 3,395.91 points Wednesday. It has gained 9.4 percent this year.