Last year Poland terminated its agreement with Russia to receive Russian gas via the Yamal pipeline after Warsaw rejected a demand to pay for the fuel in roubles and Moscow responded by cutting off supplies.
Europol Gaz has been demanding compensation for lost revenue and for a lack of gas transmission through Polish territory from 2023 to 2045.
State controlled Polish refiner Orlen took over the Polish section of the Yamal pipeline in October. That meant Gazprom would no longer have a stake in Europol Gaz, which owns the Polish part of the Yamal pipeline. Previously Orlen and Gazprom both had 48% stakes in Europol Gaz.
The St Petersburg and Leningrad Region Arbitration Court said it was banning Europol Gaz from continuing with its proceedings in Stockholm and would impose a fine of $285 million and 5.35 billion zlotys ($1.28 billion), to be converted into roubles, should it fail to comply.
Russia's Interfax news agency reported that the dollar fine was related to gas transport through Poland in 2006-2009 and the zloty fine was for losses incurred. Reuters could not immediately determine why the proposed fines were structured in that way.
Gazprom and Orlen did not immediately respond to Reuters requests for comment.
The decisive part of the decision was published on Oct. 26, with the full text of the decision only published on Oct. 31 the court said. Russian news agencies first reported the decision on Thursday.
($1 = 4.1825 zlotys)
(Reporting by Reuters; additional reporting by Marek Strzelecki in Warsaw; Writing by Felix Light; Editing by Alexander Marrow and David Evans)