"Economic growth in Russia should stay dynamic in the first half of this year but we anticipate that the economy will lose some steam in the second part," S&P chief economist Jean-Michel Six wrote in a report.
The agency said Russia may be hurt by accelerating capital outflows and political risks linked to March 4 elections that have been preceded by a wave of protests against Prime Minister Vladimir Putin's likely return as president.
Putin last month warned that 2012 will be a tougher year for Russia due to financial uncertainties in Europe and lagging growth in the world's leading economies.
He previously predicted annual growth to average some four percent over the coming three years.