KYIV, Aug 8 – Naftogaz Ukrayiny will expand the claim against Russia's Gazprom over the transit contract in the Arbitration Institute of the Stockholm Chamber of Commerce from $13 billion by $5 billion. The company is waiting for the decision by December 2017, Naftogaz Ukrayiny Chief Commercial Director Yuriy Vitrenko said.

"We are waiting for the decision regarding our claims over the transit contract. Gazprom also has a claim, but for a small sum [around $7 million]. Our claims are over $13 billion – they have been announced. We would announce $5 billion more," he said in an interview with Channel 5 television.