BEIJING - China's stock index futures closed lower on Friday with the contract for August, the most actively traded, down 2.27 percent from the previous day to 2,896.2 points.

The September contract closed down 2.29 percent to 2,906 points. The December contract declined 2.16 percent to 2,951.6, while the March contract for 2012 was down 2.07 percent, to 2,997.4 points.

The stock-index contracts, agreements to buy or sell the Hushen 300 Index at a preset value on an agreed date, are designed to allow investors to bet on and profit from both gains and declines in the market.

The index futures was launched at the China Financial Futures Exchange (CFFEX) and started trading from April 16, 2010. The CFFEX has set the base value for all the four contracts at 3,399 points.