BEIJING - The People's Bank of China (PBOC), the central bank, added more cash into banks through open market operations this week after seeing actual liquidity drain for four weeks.

An additional 11 billion yuan (1.77 billion U.S. dollars) of capital has flowed in the market this week from the previous week.

The bank on Thursday unleashed 117 billion yuan into the market after completing seven-day reverse repurchase agreement (repo) operations worth 45 billion yuan and 28-day reverse repo operations worth 72 billion yuan.

The bank on Tuesday finished 97 billion yuan in reverse repos.

This week, 50 billion yuan of central bank bills and 253 billion yuan of reverse repos matured, which meant that 203 billion yuan of liquidity was drained.

As a result, the bank injected 11 billion yuan in net liquidity after four weeks of net liquidity draining.

The central bank is less likely to lower the reserve requirement ratio within this year, as liquidity will be relatively rich by the end of the year, said a report from Bank of Communications.

Since June, the central bank has resorted to reverse repos, a more cautious, targeted and short-term tool than lowering banks' reserve requirement by buying securities held by commercial banks to improve the cash flow in the money market.