weighted average dollar exchange rate on tomorrow deals amounted to 29.25 RUR/USD at a special session at 11:30 Moscow time. It means that the official dollar rate for December 24 will be RUR0.02 lower. Yesterday, the dollar gained RUR0.02. Today's retreat in the dollar rate could have been more considerable, if the Russian Central Bank had not made a ruble intervention, commercial bank dealers told RBC. They noted that the Central Bank was purchasing dollars at 29.2450 RUR/USD preventing further strengthening of the national currency. The Bank made its interventions on the same level on December 17 to 19. At the same time, today's intervention is much larger than in the above-mentioned period. Experts say that the Central Bank bought at least $100m in the first 90 minutes of the special session this morning.