WARSAW (Reuters) - Poland's anti-monopoly body UOKiK said on Friday it had fined France's Engie Energy ENGIE.PA, one of five European firms responsible for financing gas pipeline Nord Stream 2, 40 million euros ($44 million) as part of proceedings against Gazprom.

UOKiK said Engie had refused to provide it with documents and information about the agreements it signed with Russian gas supplier Gazprom GAZP.MM.

“The company has stubbornly and in an unjustified way refused to give us the documents and materials we demanded. It caused a significant delay in our actions regarding the financing of Nord Stream 2,” UOKiK’s deputy head said in a statement.

Nord Stream 2 is led by Gazprom, with half of the funding provided by Germany's Uniper UN01.DE and BASF's BASFn.DE Wintershall unit, Anglo-Dutch company Shell RDSa.L, Austria's OMV OMVV.VI and Engie.

“We challenge the legal basis of the decision and we will appeal,” a spokesman for Engie said in Paris.

Poland sees the pipeline, which would double Russia’s gas export capacity via the Baltic Sea, as a threat to Europe’s energy security and argues it will strengthen Gazprom’s already dominant position on the market.

In 2016, UOKiK said the Nord Stream 2 project would undermine competition and rejected a planned joint venture between Gazprom and its European partners.

The companies gave up on the joint venture plan and withdrew the request for UOKiK approval.

Nord Stream 2 said the Polish anti-monopoly office’s move did not relate to the implementation of the pipeline project as such.

“The implementation of Nord Stream 2 is based on and in compliance with all applicable laws and regulations. Nord Stream 2 has received all necessary permits from all countries whose waters and territories it passes and continues as planned,” the consortium said in emailed comments.

“Nord Stream 2 does not undermine gas market competition but, on the contrary, improves it.”

Last year the watchdog launched proceedings against these companies, arguing that they had not observed its objections.

Last week, Denmark gave the go-ahead to Nord Stream 2, removing the last major hurdle to the completion of the Russian-led project that has divided opinion in the European Union.