(Yicai Global) Nov. 6 -- China's mainland stock markets tumbled in the morning session as investors' heavy selling forced major equity benchmarks to give back a big chunk of their earlier gains of this week with growth stocks losing the most.

The Star 50 Index, which follows tech stocks on Shanghai’s Nasdaq-style board, was down 2.71 percent to 1,435.45 by the lunch break. The ChiNext Price Index, which tracks growth stocks in Shenzhen, slid 2.75 percent to 2,711.29.

The Shanghai Composite Index fell 0.71 percent to 3,296.45. The Shenzhen Component Index stood at 13,724.23, down 1.22 percent.

Editor: Emmi Laine