PRAGUE -- Russia has agreed to pay back loans from the Czech Republic totaling some $3.5 billion based on an exchange rate of one dollar for one ruble of debt, Czech Premier Vaclav Klaus said. "The main success (of the agreement) is the confirmation of the exchange rate between many dubious currencies, meaning the exchange of the ruble to the American dollar at the rate of one-to-one," Klaus told reporters Wednesday. He said that the loans given to the former Soviet Union and assumed by Russia after the Union was dissolved were a mix of various currencies, with disparate exchange rates at the times the loans were made. The agreement called for Russia to pay back the debt in various installment plans, to conclude by 2003. Klaus said $544 million in principle on the loans is to be paid beginning with $52 million in 1994, $101 million in 1995, and $391 in 1996. Russia would begin interest payments of $1.8 billion in 1999, the Czech deputy finance minister, Vladimir Rudlovcak, said after the May talks.