Ratings agency Standard and Poor's said on Friday that it planned to complete a review of Russia's sovereign credit rating by the end of January, after earlier saying it expected to make a decision by mid-January.
S&P currently rates Russia's sovereign debt one notch above 'junk' status, and Russian markets have been jittery over the prospect of a downgrade.
A downgrade would mark the first time in more than 10 years that Russian sovereign debt has been rated below investment grade.