The central bank bought treasuries from five lenders and will sell them back August 23.
It was the largest liquidity boost since February 24, when the central bank pumped RON6.4 billion.
Dealers said that at the auction even large banks took part, as some lenders might face difficulties in attracting funds on the inter-bank market to build their minimum mandatory reserves.
On the money market Tuesday morning, overnight rates were flat on the day at 5.8%-6.2% a year. (EUR1=RON4.2706)