SHANGHAI, Aug 17 (Reuters) - China's major stock indexes opened down on Wednesday after the approval of the launch of a long-awaited scheme to allow stock trading between Hong Kong and Shenzhen, the world's second-busiest, and tech-heavy, exchange.
The CSI300 index which tracks the largest listed companies trading in Shanghai and Shenzen fell 0.2 percent to 3,370.44 points at 1:36 GMT, while the Shanghai Composite Index lost 0.4 percent to 3,098.51 points.
The ChiNext growth board index in Shenzhen opened flat, and was down around 0.1 percent in early trade.
China CSI300 stock index futures for August fell 0.3 percent, to 3,368, 2.44 points below the current value of the underlying index.
The Hang Seng index in Hong Kong was unchanged at 22,913.78 points. (Reporting by Nathaniel Taplin and Pete Sweeney; Editing by Simon Cameron-Moore)