Rio Sul Serviços Aéreos Regionais was a regional airline, operating scheduled services to southern Brazil. Its main base was Congonhas Domestic Airport Sao Paulo.
In 1975 the Brazilian Federal Government created the Brazilian Integrated System of Regional Air Transportation and divided the country in five different regions, for which five newly-created regional airlines received a concession to operate air services. RIO-SUL Serviços Aéreos Regionais S/A was the fourth of those regional airlines to be made operational. Rio Sul had its services start in 1976. Its operational area comprised roughly the Southern and parts of the Southeast regions of Brazil.
In 1992 the National Conference of Civil Aviation abolished the geographical division of the country and allowed further expansion in national and regional routes, prompting Rio Sul to acquire Nordeste Linhas Aereas Regionais in 1995. In 2002 the administration of Rio Sul (which included its former subsidiary Nordeste) were merged with Varig.
Source: Wikipedia
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