Carrefour S.A. (French pronunciation: ​[kaʁfuʁ]) is a French multinational retailer headquartered in Boulogne Billancourt, France, in Greater Paris. It is one of the largest hypermarket chains in the world (with 1,452 hypermarkets at the end of 2011), the fourth largest retail group in the world in terms of revenue (after Wal-Mart, Tesco and Costco), and the third in profit (after Wal-Mart and Tesco).