The average weighted rate, set at a joint trading session of eight exchanges across the country, serves as the basis for the central bank's dollar/rouble rate the following day.

Versus the euro, the rouble firmed slightly to a weighted average for today's settlement of 40.4546 at the end of official trade, compared with 40.4719 in the previous session.

Against the central bank's basket, made up of 0.55 dollars and 0.45 euros and used as a guide for exchange rate policy, the rouble was flat at 33.60.