Russian stocks and the ruble rose on Wednesday after a long plunge, thanks to a pick-up in oil prices and intervention by the Russian central bank.The average-weighted exchange rate of the Russian ruble with tomorrow settlement grew 4 kopecks against the dollar to 32.63 on Wednesday amid a positive external background and higher world oil prices.The value of the bi-currency basket, comprising $0.55 and 0.45 euros, increased 6 kopecks to 37.48 rubles as of 10:01 a.m. Moscow time, two kopecks short of the central bank's upper band of the currency corridor.International oil prices grew to about $101.5 per barrel from nearly $100 on Tuesday.The Russian ruble-denominated RTS stock index grew 0.88 percent to 1,235.75 by 11:30 Moscow time, while the index of the dollar-denominated MICEX exchange went up 1.04 percent to 1,280.90."Asian markets are trading with small losses at mid-afternoon as the prevailing mood remains one of risk-phobia. However, the overnight gain in the price of oil has helped Moscow's markets to open with a partial reversal of yesterday's big loss. Investors will, however, again wait to see how Europe's bourses and, later, the US markets react to the Italian downgrade and further cautious statements about European solvency risk," Troika Dialog said in its research note.Moody's international rating agency downgraded Italy's credit rating of state bonds by three notches, to A2 from Aa2, with a negative outlook, as it forecast further risks for eurozone amid economic instability. The agency also said that it might cut ratings of some EU members with the credit rating position below AAA over worries about the eurozone's future.In Europe, the FTSE100 rose 1.98 percent to 5,042.38, the DAX grew 1.77 percent to 5,308.93, the CAC40 went up 2.26 percent to 2,914.92 as of 11:30 a.m. Moscow time.Central bank head Sergei Ignatyev said on Wednesday the bank had sold $1.15 billion on the domestic market on Tuesday and some $8 billion in September to prevent the ruble weakening.