Vale SA

Making our list at number four is Brazilian conglomerate Vale SA which earned $48.9 billion in 2013.

The company, which is the largest producer of iron ore in the world and second biggest nickel producer, operates three of the iron ore mines in the world. The metal represented 58 percent of the company’s total revenue in 2013 with base metals nickel, copper, gold and platinum contributing 14.9 percent of the revenue.