A riot police officer walks past colleagues standing guard outside the lower house in Mexico City, after Mexico Congress approves the biggest oil sector shake-up December 12, 2013. Mexico's Congress ... more 
A riot police officer walks past colleagues standing guard outside the lower house in Mexico City, after Mexico Congress approves the biggest oil sector shake-up December 12, 2013. Mexico's Congress on Thursday overwhelmingly voted to open up the country's oil and gas sector to private investment in the biggest overhaul of the industry since it was nationalized in 1938. After a whirlwind final passage through Congress, President Enrique Pena Nieto's bill will offer companies the chance to operate oil wells, commercialize crude and partner with state oil giant Pemex as Mexico seeks to revive flagging output. REUTERS/Henry Romero (MEXICO - Tags: CIVIL UNREST POLITICS ENERGY BUSINESS) less 
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Reuters | Photo By HENRY ROMERO / REUTERS
Thu, Dec 12, 2013 6:31 PM EST