KIEV, July 9 - Gazprom's decision to halt prepayment of natural gas transit fees to Naftogaz until at least 2015 creates the potential for modest supply disruptions in Southeastern Europe this winter due to low levels of gas in Ukraine's storage facilities, Fitch Ratings reported.

"The move is a further blow to Naftogaz, which depends on revenues from the transit of Russian gas to Europe," reads the report.