BEIJING -- China's stock index futures closed mixed on Wednesday, with the contract for July 2013, the most actively traded, up 0.02 percent to close at 2,122.4 points.

The August contract edged down 0.04 percent to 2,125.4 points. The September contract added 0.07 percent to 2,129.2 points, while the December contract went down 0.25 percent to 2,148.6 points.

The stock-index futures 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.