He began his professional career in 1980 at McKinsey where he remained for five years. Shortly thereafter, he embarked on a long working relationship with the Carlo De Benedetti Group, initially at Cir, the group's holding company where he served as general manager until 1990. In 1991, he became general manager of Arnoldo Mondadori Editore and, subsequently, of Gruppo Editoriale L'Espresso. Continuing his working relationship with the Cir Group, Passera served as co-managing director of the Olivetti Group from September 1992 to July 1996, a period when the IT company expanded into telecommunications with the creation of Omnitel and Infostrada.