MOSCOW, March 20 (RIA Novosti) - Russia's largest independent gas producer Novatek's net profit, calculated to Russian Accounting Standards (RAS), fell 11% in 2008 to 14.456 billion rubles ($431.4 million), the company said Friday.

Earlier Novatek said its net profits calculated to International Financial Reporting Standards (IFRS) had increased 22% year-on-year in 2008 to 22.9 billion rubles (about $664 million).

Novatek said the drop in RAS profits was caused by exchange rate differences due to the growth of the U.S. dollar against the ruble.

The firm's gas fields are located in the Yamal-Nenets Autonomous Area in West Siberia, which has the world's largest natural gas reserves. The region accounts for over 90% of Russian natural gas output and around 20% of global gas production.