BEIJING -- China's stock index futures closed mixed on Thursday, with the contract for July 2013, the most actively traded, staying flat at 2,119.0 points.

The August contract fell 0.03 percent to 2,121.2 points. The September contract gained 0.06 percent to 2,127.0 points, while the December contract edged up 0.05 percent to 2,147.6 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 either gains or 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.