At 0730 GMT, the rouble was 2.1 percent weaker against the dollar at 81.84 and had lost 2.2 percent to 88.97 versus the euro.
Brent crude oil, a global benchmark for Russia's main export, was down 2.9 percent at $29.62 a barrel.
The rouble had hit a historic low of 86 per dollar on Thursday but surged on Friday when the oil price had jumped.
However, oil has resumed its descent this week, extending losses on Tuesday as worries about oversupply combined with more signs of a Chinese economic slowdown.
Russian share indexes were down in dollar terms but flat in rouble terms, reflecting the weaker rouble.
The dollar-denominated RTS index was down 3.1 percent to 661 points, while the rouble-based MICEX was flat at 1,717 points.