BEIJING — China's central bank for the first time used 63-day reverse repos to boost market liquidity before the end of the year, according to a statement released Friday.

The People's Bank of China (PBOC) injected 50 billion yuan (about $7.5 billion) through 63-day reverse repos, a process in which the central bank purchases securities from commercial banks with an agreement to sell them back in the future.

With an interest rate of 2.9 percent, the operations will mature on Dec 29, the last trading day of this year, meaning that the banking sector will see a steady liquidity boost during a relatively long period.

Previously, the longest term for PBOC reverse repos was 28 days.

On Friday, PBOC also boosted liquidity by 60 billion yuan through seven-day reverse repos and by 30 billion yuan with 14-day reverse repos.

Offset by maturing reverse repos, net liquidity injection stood at 90 billion yuan on Friday and 390 billion yuan for this week.