In this Nov. 27, 2008 photo, pedestrians walk past the head offices of mining giant BHP Billiton in Melbourne, Australia. BHP Billiton Ltd. said Friday, July 15, 2011 that it would buy U.S.-based oil ... more 
In this Nov. 27, 2008 photo, pedestrians walk past the head offices of mining giant BHP Billiton in Melbourne, Australia. BHP Billiton Ltd. said Friday, July 15, 2011 that it would buy U.S.-based oil company Petrohawk Energy for $12.1 billion in cash, giving the world's largest miner greater access to U.S. shale gas assets. (AP Photo/Scott Barbour) less 
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Associated Press | Photo By Scott Barbour
Thu, Jul 14, 2011 11:02 PM EDT