BEIJING, Oct. 30 (Xinhua) -- China's central bank drained 120 billion yuan (about 17 billion U.S. dollars) from the financial system through open market operations Tuesday. The People's Bank of China (PBOC) didn't pump any money into the market through reverse repos, with 120 billion yuan of contracts maturing, leading to a net withdrawal of 120 billion yuan.

A reverse repo is a process by which the central bank bids and buys securities from commercial banks with an agreement to sell them back in the future. The PBOC said the move is to keep liquidity in the banking system at a reasonable and ample level.

The overnight Shanghai Interbank Offered Rate (Shibor), which measures the cost at which banks lend to one another, dropped 28.60 basis points to 1.566 percent Tuesday.

Chinese authorities have pledged to continue a prudent and neutral monetary policy and properly deal with the relationship between stabilizing growth, deleveraging and strengthening regulatory control.