MOSCOW, June 24 (RIA Novosti) - Russian oil export duty could reach a record $495 per ton from August rising by more than 24%, a deputy head of the Finance Ministry customs payment department said on Tuesday.

"The average [crude] price was $122.1 per barrel for the May-June 23 monitoring period. It is most likely, that the average price during all the May-June monitoring period will be $122-123 per barrel. We are reaching the $490-495 level for oil export duty," Alexander Sakovich said adding that from June 1 the duty was set at $398.1 per metric ton.

He said export duties on light oil products could rise to around $345 per metric ton from August 1, 2008 (compared to the current $280.5), and duty on heavy petroleum products could increase to $185 from $151.1 per metric ton.

Russia's government adjusts export duties for crude and petroleum products from Russia every two months depending on changes in the price of Urals crude on world markets.