The long-term local currency rating was also lowered to BBB+ from A-, while the short-term local currency rating was affirmed at A-2, S&P said.
"The lowering of the ratings on Russia reflects risks associated with the sharp reversal in external portfolio and other investment flows, which has increased the cost and difficulty of meeting the country's external financing needs," Standard & Poor's credit analyst Frank Gill said.
Since August 2008, Russia's international reserves, which hold gold and foreign currency, have plunged from $583 billion to $455 billion, amid the financial crisis.
"Pressures on the financial account stem from corporations prepaying or hedging foreign exchange borrowing, from banks refinancing their foreign currency obligations domestically with public sector banks, and from resident capital flight, while the central bank tries to offset intensifying pressures on the nominal exchange rate," S&P said.
