Russia's Gazprom says has started terminating gas contracts with Ukraine

MOSCOW – Russia's gas giant Gazprom has started a procedure to terminate contracts with Ukrainian energy firm Naftogaz in an arbitration tribunal in Stockholm, Gazprom deputy CEO Alexander Medvedev said on Saturday.

Gazprom said on Friday it would end the contracts after losing a court case, escalating a dispute which has left Ukraine struggling to stay warm and which the EU said could threaten gas flows to Europe.