By 0850 GMT, the benchmark dollar-denominated RTS index fell 1.3 percent to 1,712.9 points, and the rouble-traded MICEX bourse 0.7 percent to 1,585.9 points, underperforming a 0.8 percent fall for the MSCI emerging market index. The correction came chiefly in response to US Federal Reserves Chairman Ben Bernanke's stopping short of promising a third wave of quantitative easing to aid the economy. Trading volumes this week have been weak, with investors unwilling to risk opening positions before the Sunday vote. "Politics are still at center stage in Moscow," analysts at Troika Dialog wrote in their morning research note. Prime Minister Vladimir Putin is widely expect to win a return to the presidency, but there is still uncertainty over the level of his support and analysts are worried that already-planned opposition protests may bring volatility into the market. Russia's No.2 oil producer, LUKOIL will report its 2011 financial results on Thursday. Analysts polled by Reuters expect the company to post a 31 percent year-on-year increase in net profit. The company's shares were trading down 0.3 percent on MICEX, a touch better than the whole oil and gas index, which was down 0.6 percent. The rouble fell 0.85 percent against the dollar to 29.32 .against the dollar, having lost support from the end of a monthly tax period. Oil prices remained broadly supportive. At $122 per barrel of Urals, Russia's chief blend, they are solidly above the $100 average envisaged in this year's budget. Against the euro the rouble was up 0.1 percent at 39.09 but it was down overall by 0.35 percent to 33.71 versus the dollar-euro basket the central bank uses to monitor the currency's nominal exchange rate. "We think the correction in rouble could continue in the near future, and our target of 33.90 for the basket still seems reasonable," analysts from Russian bank VTB said in a note to clients. "Nevertheless, we believe it would be beneficial to use this opportunity to establish rouble longs as global risk sentiment is still supportive of emerging market currencies." The non-deliverable forward (NDF) curve -- a barometer of market sentiment towards the currency -- has remained almost flat in recent weeks, suggesting that investors are not thinking of ditching the rouble en masse in the short- to mid-term. The one-month NDF rouble rate oscillated around 5 percent for most of February and, much higher than the 3 percent seen before the autumn wave of the euro debt crisis, but also significantly lower from the 6-7 percent seen in late 2011. Rates have slipped this week and VTB analysts expected the trend to continue, suggesting that investors will be less inclined to ditch the currency in the short-term. "We think ongoing liquidity injections from central bank are fuelling liquidity and driving rates lower," they said. The central bank has increased its injections of liquidity in the past two weeks via its one-day repo auctions. On Thursday, banks borrowed 55.3 billion roubles ($1.89 billion) via one-day repo.