Russia's Gazprom said Wednesday its gas exports to countries outside of the former Soviet Union dropped by more than a quarter year-on-year between January and May after losing several European clients.
Exports to countries outside the region totalled 61 billion cubic metres, a 27.6 percent fall from the same period last year, the energy giant said in a statement.
Since Russian President Vladimir Putin sent troops into Ukraine on February 24, Moscow has demanded that clients from "unfriendly countries" -- including EU member states -- pay for their gas in rubles.
The new requirement is seen as a measure to sidestep Western financial sanctions against Russia's central bank imposed over Moscow's offensive in Ukraine.
So far Poland, Bulgaria, Finland and the Netherlands have had their natural gas deliveries suspended over refusing to pay in rubles.
EU countries have scrambled to reduce their dependency on Russian energy but are divided about imposing a natural gas embargo as several member states are heavily reliant on Moscow's energy supplies.