Ukrtransgaz, a subsidiary of Naftogaz Ukrainy, has stored up over 20 billion cubic meters of gas in underground storage facilities, Ukraine's Energy and Coal Industry Minister Yuriy Boiko said during an interview with the newspaper Uriadovy Kurier.

"In preparations for the heating season, we've stored up over 20 billion cubic meters of gas. Gas reserves are at last year's level. Coal is around a million [tonnes], more than in 2011," he said.

Ukraine possesses 13 underground gas storage facilities with active capacity for over 31 bcm. Ukrtransgaz operates 12 of these facilities and the trunk gas pipeline system. The remaining facility is run by Chornomornaftogaz, in which Naftogaz Ukrainy owns 100%.

Naftogaz Ukrainy unites Ukraine's largest oil and gas production enterprises. The company holds the monopoly for transit and underground storage of natural gas, as well as the transport of oil via pipelines in Ukraine.