The average-weighted dollar exchange rate did not change in the first half of this morning's session on US currency and remained at the 31.68 RUR/USD level. At the same time the current situation on the market of ruble resources is promoting an advance in the dollar exchange rate. Balances of correspondent accounts at Russian commercial banks increased noticeably at the beginning of business today. This has happened for the first time since October 1. As a result, the one-day ruble credit rate has been from 4 to 6 percent, which is quite low. Yesterday afternoon the overnight ruble credit rate was even lower, some three percent, experts of commercial banks pointed out in an interview with RosBusinessConsulting.