The company logo of Russian natural gas producer Gazprom is seen on an advertisement installed on the roof of a building in St. Petersburg in this November 14, 2013 file photo. As bankers, traders and... more 
The company logo of Russian natural gas producer Gazprom is seen on an advertisement installed on the roof of a building in St. Petersburg in this November 14, 2013 file photo. As bankers, traders and investors gathered at Gazprom's London offices for its annual champagne reception, the message from the world's most powerful gas trader was clear: the Russians don't want another gas war with Ukraine. Photo taken with long exposure. REUTERS/Alexander Demianchuk/Files (RUSSIA - Tags: BUSINESS ENERGY POLITICS) less 
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Reuters | Photo By ALEXANDER DEMIANCHUK / REUTERS
Thu, Mar 6, 2014 2:41 PM EST