Canalcliente Movistar, Spain – www.canalcliente.movistar.es
Quote from Wikipedia:
The Movistar name has been in use in Spain since the launch of GSM services in 1995. After purchasing Bellsouth mobile operations branch in South America, the name became effective worldwide on April 5, 2005.
After the purchase of O2 in 2005 by Telefónica S.A., the company announced that the O2 brand would continue to be used in the UK, Germany and the Republic of Ireland, as a separate branch with its own board and management structure. Eurotel in the Czech Republic was rebranded as Telefónica O2 Czech Republic, as opposed to Telefónica Móvistar, it is possible Telefónica will expand the use of the O2 brand.
It is the biggest carrier in Spain with 22 million customers (cellphone services only) and it also has the widest coverage in Spain. It offers GSM 900/1800 MHz (2G), UMTS 2100 MHz (3G) and HSDPA (3.5G) services.