Russia's dollar-denominated RTS stock exchange index rose 0.47 percent compared to the previous close, while the country's ruble-denominated MICEX index grew 0.52 percent at closing on Thursday.
As of 18:45 Moscow time, the RTS index amounted to 1,544.83, the MICEX to 1,438.91.
The Russian stock market joined the panic on international trading floors on Friday when S&P took the decision to cut the U.S. top rating by one notch to AA-plus over concerns of America's growing budget deficit.
Late on Tuesday, the U.S. Federal Reserve System announced a decision to keep its key rate unchanged at close to zero for two more years, which led to slight stabilization on the stock markets in mid-day but rapid drop continued in the evening.