MEXICO CITY, April 20 (Reuters) - Mexican broadcaster Televisa said on Thursday it had signed a deal with Spanish telecoms giant Telefonica that would give the mobile operator's customers cheaper access to the broadcaster's content carried on its digital platform Blim.

The deal allows Grupo Televisa SA to compete with Carlos Slim's telecoms firm America Movil SAB de CV , whose Telcel mobile unit allows its clients access to entertainment offerings from Slim's Claro digital video service.

Under the terms of the deal, customers of Movistar, Telefonica's local unit, will have access to content carried on Televisa's Blim platform at a preferential rate, according to a statement.

Televisa shares were down 1.79 percent at 95.88 pesos ($5.09) in early afternoon trading.

($1 = 18.8260 pesos) (Reporting by Noe Torres and Sheky Espejo; Editing by Andrew Hay)