"Yesterday NAK Naftogaz Ukraine submitted a statement of claim in the Arbitration Institute of the Stockholm Chamber of Commerce as part of an arbitration dispute with OAO Gazprom over the gas transit contract," the statement said.
The Ukrainian energy company has been in a row with the Russian gas producer over several issues, including what it regards as "unfair" prices.
Naftogaz said it is now seeking another $10 billion in compensation from Gazprom, in addition to the $6 billion under a gas delivery lawsuit in the same court. That makes more than $16 billion in total under the both lawsuits, the Ukrainian energy firm estimated.
In October 2014, Naftogaz submitted a claim to the Stockholm court seeking a retroactive revision of its contract with Russia on natural gas transits between 2009 and 2019. It said Gazprom owed it a $3.2-billion compensation for gas that was allegedly not delivered during that period, as well as accumulated interests. The total amount claimed is in the excess of $6 billion.
In addition, the Ukrainian state-owned gas company hopes to recover up to $6 billion in alleged over-payments to Gazprom, and scrap a provision in the contract that prohibits reselling Russian natural gas outside Ukraine.
At the same time, Gazprom filed a lawsuit in the Stockholm court in an attempt to recover almost $5 billion in debt from Naftogaz. A trial's oral hearing will be held February-March 2016, a final decision is expected in late June 2016.