Vadim Chuprun, deputy director of Ukrainian energy company Naftogaz, said gas purchases from Russian would decline from around 975 billion cubic feet to about 700 billion cubic feet next year, reports state-run news agency RIA Novosti.
Gas disputes between Russian energy company Gazprom and Ukraine, most recently in 2009, caused problems for European consumers when supplies were disrupted briefly. Most of the Russian gas headed for Europe runs through a Soviet-era gas transit system in Ukraine.
European leaders aim to break Russia's grip on the regional energy sector by securing natural gas from Caspian suppliers like Azerbaijan. Russian, meanwhile, is advancing its own series of pipelines in order to avoid geopolitically sensitive territory in Ukraine.
A BP-led consortium managing the Shah Deniz II natural gas field in Azeri waters is expected by next year to make a final decision between the Nabucco West pipeline and the Trans-Adriatic Pipeline as the conduit for Azeri natural gas.
Reinhard Mitscheck, managing director of the Nabucco pipeline group, told Bloomberg News the cost of the scaled-down Nabucco West would be cheaper than the $10 billion slated for the original route. Price concerns and gas supply assurances had sparked concern from some interested parties.