MOSCOW, June 24 (RIA Novosti) - Russian energy giant Gazprom said on Wednesday there were no grounds for reviewing natural gas supply and transit contracts with Ukraine.

"I cannot see any grounds for reviewing the pricing and transit conditions," Gazprom deputy CEO Alexander Medvedev told a news conference.

Medvedev said top-class contracts stipulated the rights for the parties to review the terms and conditions but only if there were real grounds.

The gas deal the Russian and Ukrainian premiers reached on January 19 ended an almost three-week disruption in supplies to Ukraine and transits to the EU caused by a bitter pricing and debt dispute between the former Soviet allies.

Ukrainian President Viktor Yushchenko has criticized on numerous occasions the gas deals with Russia and called for a review of the gas transit tariffs, warning that otherwise Ukraine could lose $2.5 billion in 2009.