MOSCOW (AFP) – A top Russian official confirmed the existence of a contract for the supply of MiG-31 fighter jets to Syria but said work on the planes had been frozen, the daily Kommersant reported on Thursday.

"A few years ago, two contracts were signed: one for (the supply to Syria of) MiG-29s and one for MiG-31s," the head of Russia's United Aircraft Corporation, Alexei Fedorov, told the paper.

"Consultations on this contract are now ongoing, so its future is unclear."

Kommersant reported in May that Russia had halted work on the modernisation of the fighter jets at the Sokol aviation plant in the Russian city of Nizhny Novgorod.

But Russia's state arms exporter has dismissed such reports as rumours.

The 400-500 million-dollar (280-350 million-euro) contract for the delivery of eight MiG-31s fighter jets was inked in early 2007, according to Kommersant.

It cited sources close to the arms exporter in May saying the supplies of the planes had been frozen under pressure from Israel over fears the weapon sales could offset the balance of power in the region.

According to a a government official cited by Kommersant, the contract had been suspended after Damascus could no longer afford the planes.

In 2005, Moscow forgave 70 percent of Syria's total debt of 13.4 billion dollars.

United Aircraft chief Federov nevertheless told the paper the Russian planemaker was counting on completing contracts, as production at its factories has slumped amid the global financial crisis.

"Negotiations are ongoing, I hope that in the end the contracts will be realized. We put a lot of hope in it stabilizing the situation in Nizhny Novgorod," he was quoted as saying.