Trading has been halted in 1,249 shares on Chinese stock markets, Bloomberg News reported Wednesday, after hundreds of firms requested dealings be suspended as prices plunge.
The latest suspensions mean 43 percent of the companies quoted in Shanghai and Shenzhen are no longer being traded, Bloomberg said, accounting for a third of the market's capitalisation.
The fresh intervention was launched as China's benchmark Shanghai stock index plunged 6.97 percent at the opening on Wednesday despite government moves to shore up the tumbling market, dealers said.
The Shanghai Composite Index slumped 259.72 points to 3,467.40. The Shenzhen Composite Index, which tracks stocks on China's second exchange, dropped 4.07 percent, or 78.61 points, to 1,854.22.
Hong Kong stocks plunged 4.74% at the open.