Serge became a Franco-Tunisian and an expert in political economy, Adda began his vocational career in 1971 as a researcher at CETEM (Centre d'étude des techniques économiques moderne). From 1975 to 1978, he was a director of research at École Spéciale d'Architecture.
In April 2001, he became an adviser to the president of the Canal+ Horizons group.
Adda was the president of TV5 from 23 October 2001 to his death. TV5 is, after Eurosport, MTV, and CNN, the fourth-largest European broadcaster. Adda emphasized a range of popular television programs.