WARSAW--Supplies of Russian natural gas to Poland fell significantly this week, Polish companies said, a decline that hampered Poland's ability to pump gas to Ukraine in an effort to help the country as it fights Russian separatists in its east.

Poland's state-controlled PGNiG SA said Wednesday deliveries from Russia's OAO Gazprom were between 20% and 24% below contracted levels on Monday and Tuesday. State-owned infrastructure operator Gaz-System SA on Wednesday said that it had had to stop flows to Ukraine, as a result of the reduction in to Poland from Russia.

Ukraine's transport network operator Ukrtransgaz said on Wednesday that the cut was a move by Russia "to disrupt reversed deliveries from Poland."

Polish officials have for years said the Kremlin uses its gas giant Gazprom to achieve political ends. Amid previous conflicts between Russia and transit countries Belarus and Ukraine over payments and prices, Poland saw supply disruptions and had to interrupt the flow of gas to major commercial customers.

This time, PGNiG said it's compensating for the lower deliveries from the east with gas from other directions.

Gazprom wasn't available for comment.

Warsaw has expressed strong support for Kiev in its struggle with Russian separatists in eastern Ukraine. Poland supplied about 4 million cubic meters of gas a day to Ukraine, according to Ukrtransgaz. Most of that gas originates in Russia.

Another of Ukraine's neighboring members of the European Union, Slovakia has since early September pumped gas to Ukraine, with Hungary also pitching in. Late this spring Slovak Prime Minister Robert Fico estimated that maximum gas flows from Slovakia, Hungary and Poland could eventually total up to 17 billion cubic meters next year, about a third of Ukraine's total annual demand of some 50 billion cubic meters.

Russian President Vladimir Putin has repeatedly said the reverse shipments of Russian gas to Ukraine are illegitimate and that Russia would move to block them, although western officials say their contracts don't allow Russia to dictate how customers use the gas they buy.

Ukraine produces about 20 billion cubic meters of natural gas annually and, even with deliveries from its western neighbors, is likely to see a shortfall of at least 13 billion cubic meters.

PGNiG said Wednesday its storage facilities are full, ahead of the winter season. The European Union's largest emerging economy relies on Russia, its former communist-era overlord, for some 60% of the gas it consumes every year.

In recent years, Poland has been building up transport infrastructure that allows it to get gas from other directions, mostly Germany to its west and the Czech Republic to the south. It now has the ability to import 7.5 billion cubic meters of gas a year from these directions, according to PGNiG. Poland's annual gas consumption is 16 billion cubic meters.

Poland has also been building a liquefied natural gas port in the Baltic Sea but won't be able to launch it before next year.

James Marson in Moscow contributed to this article.

Write to Patryk Wasilewski at patryk.wasilewski@wsj.com and Marcin Sobczyk at marcin.sobczyk@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

Dominion Energy (NYSE:D)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Dominion Energy Charts.
Dominion Energy (NYSE:D)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Dominion Energy Charts.