WARSAW (Reuters) - Poland has appealed to the European Court of Justice over a European Commission decision to give Gazprom (>> Gazprom PAO) more capacity on the Opal gas pipeline through Germany, PAP news agency said on Sunday, citing a foreign ministry spokeswoman.

In October, the European Commission lifted a cap on Gazprom's use of the Opal pipeline, which carries gas from the Nord Stream pipeline under the Baltic Sea to customers in Germany and the Czech Republic.

The Commission's decision has opened the way for Russian plans to expand Nord Stream's capacity and bypass both Ukraine and Poland as a gas transit route. [nL8N1CY687]

Poland, which imports most of its gas from Russia, has criticised the Commission's move saying it threatened gas supplies to central and eastern Europe.

"The situation threatens the security of gas supplies in the EU, particularly in the region of Central Europe," PAP cited Joanna Wajda, the spokeswoman as saying.

"This raises a serious risk to the security of gas supply for Poland by becoming dependent on one source of supply, from Russia."

The Opal decision as well as Gazprom's plan to build a Nord Stream 2 pipeline, embody the worst fears of the Polish conservative government which sees pacts between its powerful neighbours, Germany and Russia, as an existential threat.

In December, Polish state-run gas company PGNiG (>> PGNiG SA) sued the European Commission over the decision. [nL5N1E03FA]

(Reporting by Pawel Florkiewicz; Writing by Lidia Kelly. Editing by Jane Merriman)

Stocks treated in this article : PGNiG SA, Gazprom PAO