Telecom Argentina is the major local telephone company for the northern part of Argentina, including the whole of the city of Buenos Aires. Briefly known as Sociedad Licenciataria Norte S.A., it quickly changed its name, and is usually known as simply Telecom within Argentina. Telecom Argentina's local telephone market, together with Telefónica de Argentina in the southern part of the country, was part of a duopoly until October 8, 1999. Telecom also operates mobile phone service Personal and Internet service provider Arnet.