China's central bank has promised more credit to finance stock trading in the latest move aimed at stopping a plunge in stock prices that has prompted hundreds of companies to suspend trading in their shares.

The central bank said Wednesday it would provide "ample liquidity to support stock market stability" through a government-owned company that lends to brokerages to finance share purchases.

The move adds to a flurry of increasingly frantic measures aimed at stopping a slide in which China's main stock index has tumbled nearly 30 percent since early June.

Hundreds of companies have asked the country's two exchanges to suspend trading in their shares after prices of some fell by more than 50 percent.