BEIJING, Nov. 22 (Xinhua) -- China's stock index futures opened mixed on Tuesday with the contract for settlement in November opening at 2,602.2 points, down 6 points.

The contract for settlement in December, the most actively traded, opened 8.6 points lower at 2,602 while the contract for settlement in March 2012 opened at 2,634.2 points, up 3.4 points.

The contract for settlement in June 2012 opened 7.6 points lower at 2,639.6 points.

The stock-index contracts, agreements to buy or sell the Hushen 300 Index at a present 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 were 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