BEIJING, Jan. 24 (Xinhua) -- China's central bank Wednesday pumped 220billion yuan (about 34.4 billion U.S. dollars) into the financial system through open market operations.

The operations included 110 billion yuan of seven-day reverse repos, 100 billion yuan of 14-day reverse repos and 10 billion yuan of 63-day reverse repos, the People's Bank of China said on its website.

The interest rates for seven-day, 14-day and 63-day operations were unchanged at 2.5 percent, 2.65 percent and 2.95 percent, respectively.

On Wednesday, previous reverse repos worth 170 billion yuan matured, meaning that there was a net injection of 50 billion yuan.

The central bank has increasingly relied on open market operations for liquidity management, rather than cuts in interest rates or reserve requirement ratios.

This year, monetary policy will be kept neutral and the money supply should be controlled, according to the Central Economic Work Conference held last month.