Russia's central bank is changing its exchange rate policy and will no longer use the U.S. dollar exclusively as a target for the ruble.

In a statement Friday, the Bank of Russia announced it is switching to a dual currency "basket" weighted 90 percent in dollars and 10 percent in euros, as an exchange rate guide for the ruble. The bank adds that the weighting will be readjusted gradually in the future to raise the euro's proportion in the currency basket.

The Bank of Russia indicated its decision was based in part on the dollar's recent weakness, which it says has caused "significant fluctuations" for the ruble against other currencies, including the euro, which is gaining increasing acceptance as the world's second leading currency.

Friday's move by Moscow comes less than a month after a survey of 65 central banks showed a majority are now holding fewer U.S. dollars and more euros as reserves.

The dollar has been falling against the euro and other major currencies for three years. Analysts say the ruble's shift away from reliance on the dollar could further undermine the U.S. currency's value on currency markets.

Some information for this report provided by Bloomberg and Reuters.