ST. PETERSBURG — Power firm TGK-1 said 2009 net profit rose sevenfold to 8.4 billion rubles ($266.2 million) as the firm part-canceled an impairment charge amid strong market conditions.

The company, which supplies power to St. Petersburg and Russia's northwest, said in a statement Thursday that it had gained more than 5.4 billion rubles from the accounting move, which related to two thermal power plants and a heating grid.

"Management considered recent favorable changes in operation of the Russian electricity market and resolved to partially reverse the impairment provision," TGK-1 said.

Russia's large cluster of power companies have been reporting sharply improved results in recent days on the back of recent liberalization of the electricity market.

TGK-1, part-owned by Gazprom and Finland's Fortum, posted the 8.4 billion ruble net profit figure after recording a 1.2 billion ruble profit in 2008.

Full-year revenue rose to 41.35 billion rubles from 33.6 billion rubles, while operating profit increased more than 10 times to 10.4 billion rubles.