The Russian rouble firmed towards 67 per dollar, boosted by exporting companies selling off foreign currency revenues to pay taxes later in the month and the central bank's intervention on forex markets.
The rouble was up 0.5% versus the dollar at 67.42 by 0748 GMT and had gained 0.16% against the yuan to trade at 10.01.
Against the euro, the rouble was up 0.25% at 72.97.
Brent crude oil, a benchmark for Russia's main export, rose 0.1% to $84.11 a barrel.
"The rouble has continued to strengthen its position,"Otkritie Bank research analyst Andrey Kochetkov said, adding that exporters' selling of forex revenues was the main factor supporting the currency.
The finance ministry's announcement on Wednesday that it would sell around $47 million worth of Chinese yuan daily from January 13 to February 6 has also provided some support for the rouble, which hit its highest level since late December in the previous session.
The ministry has allocated the equivalent of $800 million in total to spend on this intervention on foreign exchange markets.
"This and the approaching tax period will support the Russian currency, which now looks technically over bought," Alexei Antonov from Alor Broker said, adding that a correction for the rouble could not be ruled out.
Russian stock markets were mixed.
The dollar-denominated RTS index was up 0.41% at 1,020.06, while the rouble-based MOEX Russian index was down 0.12% at 2,183.34.
