The central bank bought treasuries from four lenders and will sell them back August 2.
Dealers said the four banks had difficulties in attracting funds on the inter-bank market as liquidity surplus keeps interest rates at low levels.
On the money market Tuesday, overnight rates rose to 5.2%-5.7% a year, from 4.1%-4.6% a year in the previous day. (EUR1=RON4.25)