BEIJING -- The rate of profit among Chinese companies declined in the first nine months of 2012, as the country's economic growth continued to slow.

The average net profit rate of 938 companies that released their third quarter reports, or more than one third of the total listed on the Shanghai and Shenzhen bourses, edged down 1.29 percentage points to 5.91 percent in the first nine months.

The average net profit rate in the third quarter dropped 0.74 percentage points from the second quarter to 5.7 percent.

Companies in property, information equipment, and building materials were among the worst hit in the July-September period, with average profit rates down 2.93, 2.35, and 2.3 percentage points, respectively. Ferrous metal sector suffered a negative profit margin.

However, six sectors, including food and beverage, public services, electronics, textile and apparel, merchandise trade, and light industry saw higher average profit rates quarter-on-quarter in the July-September period.

Out of the six sectors, profit rates of companies engaged in food and beverage, public services or electronics businesses surged in the third quarter and hit a four-quarter high.

The sluggish performance of the country's stock markets echoed the declining profitability that is hitting Chinese companies.

The benchmark Shanghai Composite Index briefly dipped below the 2,000 level for the first time since February 2009, before closing at 2,004.17 on September 27.

China's economy expanded 7.4 percent year-on-year in the third quarter, slower from 7.6 percent in the second quarter and 8.1 percent in the first, official data showed.