KIEV, Jan. 19 - Naftogaz Ukrayiny believes that the take-or-pay clause, as set out in its 2009 contract with Gazprom, is "non-market, unlawful and invalid" and therefore contests its application at the Arbitration Institute of the Stockholm Chamber of Commerce, the Ukrainian gas company said in a statement on Tuesday.

"The lawfulness of Gazprom's claims based on the take-or-pay clause will thus be decided by the court," the Ukrainian company said.