Sud Aviation eventually became part of Aerospatiale.
France had a number of state owned aircraft companies many years back that were named after where the were located in France: Nord (North), Sud (South), Sud Oust (SW), Sud Est (SE) etc. They merged in various ways over the years and became privatized or went away. Sud Aviation and Nord Aviation merged and became the foundation of Aerospatiale.
To take the provenance of Sud aviation a couple more steps, Aerospatiale eventually became part of Airbus, which became the EADS of today. So, in a sense, they're still around, and still making aircraft!