The country's largest gas company, Ukrgazvydobuvannya, has initiated proceedings with the Arbitration Institute of the Stockholm Chamber of Commerce to terminate a joint activity agreement, dated June 10, 2002, signed with Karpatygaz and Misen Enterprises AB (both companies are controlled by businessman Dmytro Firtash, according to the media), and recover losses, the press service of Ukrgazvydobuvannya reported.