Hearings by the Arbitration Institute of the Stockholm Chamber of Commerce in litigation between national joint-stock company Naftogaz Ukrainy and Russia's OJSC Gazprom over the natural gas supply and transit contracts signed early 2009 will start late September and late November or early December, respectively, Naftogaz Ukrainy Board Chairman Andriy Kobolev has said.

He said at a press conference in Kyiv on Thursday that the decision on the gas supply contract would be made this year, but it is more likely to receive it early 2017.

As reported, Naftogaz filed with the Arbitration Institute of the Stockholm Chamber of Commerce demanding that its transit contract be transferred to Ukrtransgaz and adapted to meet the requirements of the EU's Third Energy Package, and demanding to change the methods for calculating the transit tariffs in line with European standards and EU and Ukrainian energy and antimonopoly laws.

Naftogaz seeks over $11.7 billion of compensation from Gazprom. The claims concern the non-fulfillment of the contract conditions until 2015 and they will be expanded, taking into account the claims of 2015.

Naftogaz argues, with respect to its contract with Gazprom to supply natural gas signed in 2009, that the amount of its claims against the Russian company in the arbitration case that have been adjudicated since June 2014, in Stockholm, exceeds $12 billion. The claims are associated with the gas purchases made at rates higher than market ones in the period between 2010 (after the first demand was addressed to Gazprom to adjust the price according to current market levels as per the contract) and 2014.

Naftogaz insists that the "take or pay" provision is a discriminating one, hence, combined with other conditions of the contract (specifically, the formula of the price and the ban for re-exports of gas) and as such cannot be applied in this instance.