Mumbai: To tide over the current liquidity crisis, the Reserve Bank today announced that it  will purchase government securities worth 12,000 crore through open market operations.

"Consistent with the stance of monetary policy and based on the current assessment of prevailing and evolving liquidity conditions, RBI has decided to conduct Open Market Operations by purchasing government securities for an aggregate amount of 12,000 crore on January 20, 2011, through a multi-security auction...," the apex bank said in a statement.

The auction is to be conducted by the bank at its Mumbai office.

The auction will be in four price methods— government securities (G-Sec) maturing in 2017 with a coupon of 8.07 percent, G-Secs maturing in 2021 with a coupon rate of 7.80 percent, G-Secs maturing in 2022 with an 8.08 percent coupon rate and G-Secs maturing in 2032 with an 8.28 percent coupon rate.

"There is an overall aggregate ceiling of 12,000 crore for all the securities in the basket put together. There is no security-wise notified amount," RBI said.

RBI Deputy Governor Subir Gokarn had earlier said liquidity is likely to be under pressure for some more time amid factors like advance tax payment.

The RBI has said in the past that the deficit has exceeded its target of 1 percent of net demand and time liabilities (NDTL).

The apex bank has purchased government securities worth over 61,300 crore from the money markets in seven installments in the past month-and-a-half as part of efforts to infuse liquidity into the system.

OMOs are the "first preference" of the RBI while injecting liquidity and there is an opportunity to raise up to 2.74 lakh crore through the window as banks' government bond holdings stand at 29 percent, 5 percent over the prescribed SLR cap of 24 percent.