Cielos del Sur S.A., operating as Austral Líneas Aéreas, more commonly known by its shortened name Austral, is a domestic airline of Argentina, the sister company of Aerolineas Argentinas. It is the second largest domestic scheduled airline in the country, after Aerolíneas Argentinas itself. Its main base of operations is Aeroparque Jorge Newbery, Buenos Aires. Austral is currently fully integrated into Aerolíneas Argentinas.
The origins of the carrier can be traced back to 1957, when Compañía Austral de Transportes Aéreos SACI (CATASACI) was founded, starting scheduled services in 1958. In 1966, CATASACI acquired a 30% holding in Aerotransportes Litoral Argentino (ALA), a Rosario–based company that was founded in 1957 and operated flights within northern Argentina, and the services of both companies were integrated. Austral Líneas Aéreas was formally established in 1971 from the merger of CATASACI and ALA. In practice, operations of the latter airline were absorbed by CATASACI, which was rebranded as Austral Líneas Aéreas S.A. after merging. Austral became a government-owned company in 1980.