Smoke rises from the chimneys of an oil refinery near Corinth town, some 80km (50 miles) west of Athens January 24, 2012. Brent crude oil held above $110 on Tuesday as supply concerns rooted in tension between Iran and the West offset fears over demand growth stemming from protracted negotiations over Greece's debt. REUTERS/Yiorgos Karahalis (GREECE - Tags: POLITICS ENERGY BUSINESS)