BEIJING, June 6 -- China's central bank on Monday pumped more money into the market to ease a liquidity strain.

The People's Bank of China (PBOC) conducted 40 billion yuan (6.1 billion U.S. dollars) in seven-day reverse repurchase agreements (repo), a process in which central banks purchase securities from banks with an agreement to resell them in the future.

The reverse repo was priced to yield 2.25 percent, unchanged from Friday's injection of 40 billion yuan, according to a PBOC statement.

The move followed a net injection of 70 billion yuan and 95 billion yuan into the financial system on Thursday and Wednesday, respectively.

In Monday's interbank market, the benchmark overnight Shanghai Interbank Offered Rate (Shibor), which measures the cost at which Chinese banks lend to one another, dropped by 0.1 basis point to 1.998 percent after the injection.