The rouble lost about 8% against the dollar last week and is on course for a monthly decline after an oil embargo and price cap came into force. The finance ministry has said the recent slump was related to recovering imports.

At 0742 GMT the rouble was 1.2% weaker against the dollar at 70.10, but still some way off the almost eight-month low of 72.6325 struck last week.

"At the end of December, the rouble is likely to remain extremely volatile as the market will need to find a new equilibrium under changed trade flows and increased sanctions pressure," BCS World of Investments said in a note.

"This week, the rouble is expected to fluctuate in the range of 68-71 (per dollar)."

Against the euro, the rouble lost 1.1% to 74.35. Against the yuan, it was down 1.9% at 9.95.

The rouble remains the world's best-performing major currency against the dollar this year, supported by capital controls and reduced imports.

Now, with exports and revenues falling, a weaker rouble is more beneficial, the TASS news agency quoted First Deputy Prime Minister Andrei Belousov as saying on Tuesday.

"The strong rouble has played its role," Belousov said. "In these conditions ... it would be good to have a rouble rate of 70-80 per dollar."

Brent crude oil, a global benchmark for Russia's main export, was up 0.4% at $84.2 a barrel while Russian stock indexes were mixed.

The dollar-denominated RTS index was down 1.6% at 961.3 points. The rouble-based MOEX Russian index was unchanged at 2,139.5 points after touching its highest in nearly two weeks in early trade.

For Russian equities guide see

For Russian treasury bonds see

(Reporting by Alexander Marrow; Editing by David Goodman)