Jitters over rising US Treasury yields and solid US economic data sparked concerns that the Federal Reserve would pick up the pace of its interest rate hikes, boosting a broad sell-off of riskier assets on Wednesday.

Russian indexes were down to the levels last seen in mid-September.

At 0756 GMT, the dollar-denominated RTS index was down 2.1 percent at 1,119.81 points. The rouble-based MOEX Russian index was 1.8 percent lower at 2,374.05 points.

"The Russian market today, most likely, will also continue the downward movement, as it closed yesterday before the main drop of indexes in the United States," analysts at Uralsib said in a note.

Oil prices also fell amid a rout in global stock markets. Brent crude oil, a global benchmark for Russia's main export, was down 1.2 percent at $82.10 a barrel.

But the Russian rouble firmed, supported by exporters that were preparing to meet tax payments at the end of the month. Exporters usually convert foreign currency revenues into roubles to meet these duties.

"For exporters, current levels (of the US dollar) are like honey, especially before taxes," said one Russian bank dealer.

The rouble was 0.2 percent stronger against the dollar at 66.78 and was stable versus the euro at 77.06.