Telefonica operates mobile and fixed networks in Spain (where it is the incumbent telephone operator), the UK, Germany, Brazil, and other Latin American countries like Colombia, Mexico, Argentina, and Chile. The company derives more than 30% of its revenue from Spain, close to 20% from Germany, and 20% from Brazil. Its UK operations are held through a joint venture with Virgin Media. For several years Telefonica has been simplifying its corporate structure by selling noncore assets.