BEIJING - China's central bank said Thursday it will continue to support liquidity need of China Securities Finance Corporation Limited (CSF), the national margin trading service provider, to stabilize a tumbling stock market.

The People's Bank of China (PBOC) said it has made sufficient re-lending to the CSF and approved the latter to issue short-term financial bonds in the interbank market to replenish liquidity.

The CSF is the only institution to provide margin financing loans to securities companies. It has offered 260 billion yuan ($42 billion) of stock-secured credit for 21 brokerage firms to conduct self-run share purchasing on the market.

The PBOC is trying to guide more capital into the market to rein in a continued plunge and restore investors' confidence as Chinese shares have been in a downward spiral since hitting a peak in June. The benchmark Shanghai Composite Index has shed more than 30 percent.