The Russian rouble plunged to a new low on Monday as falling oil prices piled further pressure on the struggling currency.

By afternoon in Moscow the Russian central bank had set its rate for August 25 at 70,74 roubles to the dollar, marking the Russian currency's weakest point since 1998.

The announcement came after the rouble touched 71.29 to the dollar and 81,65 to the euro on Monday morning, marking the worst fall in value since a run-away devaluation over winter that forced the central bank to sell $90bn in foreign reserves to halt.

The previous record since 1998 was set in February, when the official exchange rate for the dollar hit 69,66 roubles. The euro hit 84,59 in December.

By 2pm in Moscow the rouble was trading at 70,8 to the dollar and 81.4 to the Euro.

The latest devaluation comes as oil prices plunged to a six-year low. Brent crude, the main benchmark for Russian oil, hit $44 a barrel, its lowest point since March 2009, on Monday morning.

Alexei Ukyukaev, Russia's minister of economic development, predicted oil could yet dip below $40 a barrel, "if only for a short time".

Dmitry Medvedev, the prime minister, has hinted that major Russian exporters may be compelled to sell off foreign currency reserves to bolster the falling currency.

Speaking on Saturday, Mr Medvedev said the government would "help the central bank in the sense of additional foreign currency inflows".

Rouble to US dollar 6-month change

Last Price 2/25/15 0.01629 0.01637 0.01586 0.01601 0.01616 0.01616 0.0164 0.01657 0.01652 0.01607 0.01628 0.01636 0.0161 0.01605 0.01629 0.01689 0.01666 0.01686 0.01703 0.01731 0.01744 0.01745 0.01729 0.01736 0.01718 0.01736 0.01771 0.01769 0.01806 0.01817 0.01864 0.01928 0.01866 0.01918 0.01962 0.02015 0.02008 0.01925 0.01875 0.0186 0.0192 0.0197 0.01965 0.01928 0.01947 0.0196 0.01937 0.01927 0.01919 0.01979 0.01973 0.01991 0.01959 0.0195 0.02002 0.02028 0.02 0.0202 0.02035 0.02018 0.02011 0.02001 0.02 0.02002 0.01964 0.01932 0.01899 0.01911 0.01867 0.01894 0.01841 0.01774 0.01778 0.01792 0.01804 0.01842 0.01828 0.01812 0.01834 0.01856 0.01864 0.01871 0.01848 0.01854 0.01858 0.01836 0.01827 0.01825 0.01796 0.01807 0.01791 0.01802 0.01787 0.01759 0.01764 0.01741 0.0175 0.01775 0.01768 0.01773 0.01758 0.01756 0.01755 0.01754 0.01755 0.01741 0.01731 0.01711 0.01668 0.01669 0.01705 0.01672 0.0162 0.01574 0.01587 0.01575 0.01551 0.01562 0.01588 0.01556 0.01557 0.01546 0.01541 0.01529 0.01518 0.01502 0.0147 0.01448 8/24/15 0.0141

Bloomberg

"In the near future we will launch foreign currency sales by our largest exporters, which will affect the rouble's rates. So we, together with the central bank, will undertake a definite collection of agreed measures," he said.

It is not clear what, if any, instructions have been issued to major state-owned exporters, or how much impact the plan may have on the currency markets.

Russian firms often sell of some foreign currency towards the end of the month because they need roubles to pay taxes.

Last month the central bank halted daily purchases of foreign currency in a bid to curb renewed devaluation.

Photo: Reuters

The impact was also felt on Russia's main stock exchanges.

