The deal, which still needs to be approved by both governments, follows months of negotiations between Poland and Russia and lessens risk of winter gas shortages in the ex-communist EU member country.

A major sticking point had been disagreement over the functioning of Europolgaz, a joint venture between PGNiG and Russian gas export monopoly Gazprom, which manages the Yamal pipeline in Poland.

"Both sides have agreed on increased deliveries as well as extending the existing contract until 2037. Additionally a compromise was reached regarding management at Europolgaz and its tariff policy," Reuters quoted PGNiG as saying in a statement.

According to sources close to the negotiations, under the new deal Poland will receive 11 billion cubic metres annually directly from Gazprom if the agreement is approved at an inter-governmental meeting in the first half of November.

Poland, which imports about two-thirds of gas it uses from Russia, faced an annual shortfall of 2.5 billion cubic metres from 2010 and the new deal will plug that gap.

Russia is the only supplier able to do so.

The current gas agreement between the two countries is due to expire 2022.

Poland uses around 14 billion cubic metres of gas annually, with one third coming from domestic sources, while the remainder has been imported directly from Gazprom - about 7.5 billion cubic metres - and from the now defunct intermediary RosUkrEnergo.

Warsaw could ask for some of the extra gas to be delivered as soon as this year, as cold weather might force PGNiG to cut off supplies to its largest industrial clients this winter.

"I think we will have to take in advance some of this (additional) gas already this year," a source told Reuters.

Warsaw had originally wanted to strike a deal by the end of July and to officially sign it during Russian Prime Minister Vladimir Putin's visit to Poland on 1 September, but the sides could not agree on all the issues.

Published: 30 October 2009 12:01 GMT  | Last updated: 30 October 2009 13:49 GMT