The claims of the Naftogaz of Ukraine national joint-stock company to the Russia's gas monopoly Gazprom exceed USD 12 billion. Senior executive director of Naftogaz Yurii Vitrenko has written this on Facebook, Ukrainian News Agency reports. As Ukrainian News Agency earlier reported, Naftogaz has held USD 9 million of Gazprom overpaid for has transit services as a part of Gazprom's debt on the decision of the Arbitration Institute of the Stockholm Chamber of Commerce (Sweden). The statement reads that Naftogaz of Ukraine sent a notification to Gazprom on the fact on October 10. The statement reads that Gazprom refuses to abide by the decision of the Stockholm Arbitration in 2018 and continues to pay a bigger price for gas transit than Naftogaz charges in compliance with the decision of the Stockholm Arbitration. Naftogaz has held USD 9 million overpaid by Gazprom for gas transit services for August as payment within the decision of the Stockholm Arbitration. Naftogaz filed a claim at the Arbitration Institute of the Stockholm Chamber of Commerce (Sweden) on July 6, asking the Arbitration Institute to revise the gas transit tariff under its contract with Gazprom. Naftogaz of Ukraine is claiming an estimated USD 11.58 billion, excluding interest The Arbitration Institute of the Stockholm Chamber of Commerce ruled in favor of Naftogaz of Ukraine on February 28 in a dispute in which it claimed USD 4.63 billion from Gazprom as compensation for failing to deliver the agreed volumes of natural for transportation on transit through Ukraine. Gazprom will have to make a net payment of USD 2.56 billion to Naftogaz of Ukraine since the arbitration institute previously ordered Naftogaz of Ukraine to pay Gazprom for gas supply arrears.