At 1600 GMT, the rouble was 0.8% weaker against the dollar at 66.59 but still at a distance from a six-month low of 67.11 touched last week. The Russian currency had opened 0.4% weaker against the greenback on Tuesday.

Versus the euro, the rouble lost 0.8% to trade at 73.69 on the day.

The rouble fell despite prices for oil, Russia's main export, rising after US President Donald Trump predicted a trade deal with China after positive comments by Beijing, calming nerves after a round of tit-for-tat tariff hikes.

Brent crude oil, a global benchmark for Russia's main export, was up 0.1% at $58.76 a barrel as of 1600 GMT.

There are no explicit internal drivers to support the rouble, said Mikhail Poddubsky, an analyst at Promsvyazbank.

The peak tax period, which usually prompts companies to convert foreign revenues into roubles, ended on Monday. Some minor taxes are still due to be paid by Russian companies this week.

Russia's Finance Ministry will auction two series of OFZ treasury bonds worth 20 billion roubles ($303.05 million) on Wednesday. Demand for these bonds, which serves as a gauge of market sentiment toward Russian assets, often buttresses the rouble.

The dollar-denominated RTS index was down 0.8% to 1,258 points, while the rouble-based MOEX Russian index was flat at 2,659 points.