BEIJING -- China's stock index futures closed more than half a percent lower on Wednesday, with the contract for October down 0.5 percent from the previous trading day to 2,584.4 points.

The November contract, the most actively traded, weakened 0.56 percent to close at 2,586 points. The December contract skid 0.58 percent to 2,591.4 points, while the March contract for 2012 went down 0.64 percent to finish at 2,617.8 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.