MOSCOW, June 20 ??“ RosUkrEnergo, a Swiss-registered gas trader thought to be controlled by Gazprom, may store extra amount of natural gas in Ukrainian underground gas tanks for the winter, a Gazprom official said Tuesday.

Alexander Ryazanov, deputy CEO Gazprom, said the move would help to reduce the risk if Ukraine fails to store enough gas amid looming shortages during the upcoming winter.