KIEV, April 27 - Naftogaz Ukrayiny, the national oil and gas company, will take steps to verify reports over ownership of RosUkrEnergo, a controversial natural gas trader and the country??™s only gas supplier, an official said.

RosUkrEnergo has been facing mounting pressure from the U.S. government over the past several months to disclose real owners amid concerns the company may have links to the organized crime.