KIEV, April 20 – The total amount of mutual claims by Ukraine's Naftogaz Ukrayiny and Russia's Gazprom lodged with the Arbitration Institute of the Stockholm Chamber of Commerce is about $50 billion, Naftogaz CEO Andriy Kobolev said.

"The total sum of both claims at Stockholm arbitration is about $50 billion," he told Channel 5 on Wednesday evening.

In this connection he asked that comments, assessments and decisions on gas issues, including Naftogaz's reorganization, should be made with caution, as they may negatively influence decision-making by the Arbitration Institute.