EU states have written to Russia and Ukraine urging them to ensure a steady flow of gas to Europe despite the two ex-Soviet republics' stand-off over prices for the key energy source, Austria said on Sunday, according to Reuters. The energy ministers of Germany, Italy, France and Austria made the appeal in joint letters sent to Moscow and Kiev on Saturday, before Russia cut gas supplies to Ukraine in a move that could hamper deliveries onwards into the European Union. Russian state monopoly Gazprom said it had cut supplies to Ukraine by a quarter -- the level of Ukraine's own imports -- after Kiev refused to sign a new contract requiring it to pay four times as much. In a letter to Moscow, the four EU states said: "May we remind you that Gazprom and companies operating in the states of the undersigned ministers have entertained close business relationships for years and that, not least because of the reliability of gas supplies from Russia, the sales of natural gas in the EU could be continuously increased in recent times. "A reduction of natural gas supplies at this point in time would not only come unexpectedly but could also lead to not insignificant problems for natural gas supplies in Western Europe," the letter said. "In view of existing excellent relations between (our four) states and your country may we assume that, irrespective of whether Russia and the Ukraine reach an agreement on the terms of future gas supplies, the supplies to the EU member states will be maintained to their full extent." The letter to Ukraine was identical except for a passage reminding Kiev of "years of excellent relations" between the EU states and the ex-Soviet republic which they said had intensified since a pro-Western government took office a year ago.