KIEV, Jan. 13 – Switzerland's RosUkrEnergo (RUE) has bought controlling stakes in Ukrainian regional gas supply companies and controls 75% of the gas sales in Ukraine through them, Dmytro Firtash, RosUkrEnergo co-owner, said.

"One should understand that RUE bought controlling stakes in regional gas supply companies in Ukraine and controls 75% of gas sold in Ukraine," he said in an interview with the Vedomosti newspaper published on Sunday.