Workers clean the windows of the Organization of the Petroleum Exporting Countries (OPEC) headquarters in Vienna April 7, 2014. Brent crude oil fell below $106 a barrel on Monday, snapping a two-day rise, after Libyan rebels occupying four eastern oil ports agreed to end an eight-month blockade, raising the prospect of increased supply to world markets. REUTERS/Heinz-Peter Bader (AUSTRIA - Tags: BUSINESS LOGO ENERGY EMPLOYMENT)