Moscow - Falling energy prices and the ongoing financial crisis have pushed the Russian rouble to an historic low against the dollar, according to the Russian central bank.

As reported by Interfax, the bank moved Thursday for the fourth time since the start of the year to broaden the range for currency fluctuations versus a basket of currencies comprised of the dollar and the euro.

The official exchange rate was posted at 32.21 roubles to the dollar, a rate 65.19 kopeks higher than on Wednesday.

The previous low of 31.88 roubles to the dollar was hit six years ago, according to Interfax.

Russia's central bank has set aside tens of billions of dollars in recent months to prevent a dramatic downgrade in the rouble's value. But, since pressure on the rouble did not let up, the bank took the additional step of devaluation Thursday.

Russian experts expect that this trend to continue in the near future since the central bank plans to stop taking actions on currency markets to supports its reserves.

Since February 2005, the rouble's value has been fixed against the currency basket, in which the dollar carries a 55-per-cent weight and the euro the rest.

Since mid-May, Russian authorities have allowed the rouble's value to fluctuate in a range.

During that time, it has lost 20.4 per cent of its value versus the currency basket.

The rouble also lost ground against the euro on Thursday, falling to 42.38 roubles for one euro. (dpa)