Exclusive: Mexican broadcaster Televisa to launch mobile phone service, challenging Slim

Mexican broadcaster Televisa said on Sunday it will start offering mobile phone service, a bid to challenge billionaire Carlos Slim's America Movil, which has long dominated the country's telecommunications market.Rather than building infrastructure, Televisawill operate as a mobile virtual network operator, or MVNO, and begin by offering service to existing customers of its cable and home internet packages, sold under its Izzi brand.Televisa originally planned to roll out the service in Septemb