The leu opened at 4.250/4.2535 to the euro, close to 4.248/4.250 at closing the day before.
Later, the leu started strengthening and, at around 10:20 local time, it was trading at 4.2425/4.245 to the euro.
The central bank set Monday a reference rate of 4.2527 lei to the euro, slightly weaker than the previous reference.
On the money market, overnight rates rose to 5.5%-6% a year, from 4.1%-4.6% a year.