BEIJING - China's stock index futures closed mostly lower on Friday, with the contract for September rallying 3.4 points, or 0.13 percent, to close at 2,593.0.

The contract for February, the most actively traded, lost 2.8 points, or 0.11 percent, to close at 2,531.404.4 points, much lower than 2,351.98 points on the spot market.

The March contract was almost unchanged at 2,542.8 points, down 0.8 points. The June contract skid 1.4 points, or 0.05 percent, to 2,564.4 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 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.