MOSCOW, May 20 (RIA Novosti) - Russia has put on a hold a contract to deliver MiG-31E Foxhound interceptor-fighters to Syria, a Russian business daily reported on Wednesday, citing defense-industry sources.

According to Kommersant, the $400-500 million contract for the delivery of eight MiG-31E aircraft was signed in 2007. Since production of MiG-31E's had stopped in 1994, Syria was to receive retrofitted aircraft from Russia's Air Force reserves.

There has been no official comment on the decision to freeze the contract, but an industry source quoted by the daily said the contract was terminated due to Damascus's financial problems.

In the winter of 2005, Russia forgave 70% of Syria's debt, which at the time stood at $13.4 billion. After that Damascus still owed Moscow $3.6 billion.

Later in the year, Russia resumed military cooperation with Syria, delivering, in particular, Strelets surface-to-air missile systems.

Earlier this month, some Russian and foreign media reported Belarus was planning to sell S-300 surface-to-air missiles and Iskander tactical missile systems to Iran, and said that Tehran had arranged to transfer some of the systems to Syria. However, the Belarusian president denied the country had any plans to sell weapons to Syria or Iran.