Sanef was formed in 1963 to operate the Paris-Lille motorway (A1). Sanef's network expanded over time; the main extensions were a new concession connecting Belgium with the north and east of France (A2), and the takeover of the Paris-Metz motorway (A4). In 1994, Sanef assumed ownership of the Société des Autoroutes Paris-Normandie (SAPN) that operates a network serving the western Ile-de- France and Normandie. The Sanef and SAPN concessions were to expire on 31 December 2028.
By mid-2006, the length of the road concession network operated by Sanef was 1,083 miles. This made Sanef the third largest highway concessionaire in France and the fifth largest in Europe. The operations of this group are concentrated at the northern part of France. Sanef includes the 'autoroute du Nord', the most heavily used French motorway. Table 3 presents financial and corporate information on Sanef before privatization.