An electric connector (2, 2') having an insulating casing (4) defining a number of cavities for housing respective electric terminals and having axes parallel to a first direction (A) in which the connector (2, 2') is coupled to a complementary connector (3); a slide (16) fitted to the casing (4) to slide in a second direction (B) perpendicular to the first direction (A), and having cam-type first engaging members (22) for receiving respective second engaging members (23) on the complementary connector (3) to produce a relative coupling movement of the connectors (2, 2'; 3) in the first direction (A) when the slide (16) is moved in the second direction (B) into a fully assembled position with respect to the casing (4); and retaining means (40, 41, 62) for keeping the slide (16) partly connected to the casing (4); the retaining means (40, 41, 62) being selectively deactivated when coupling the connector (2, 2') to the complementary connector (3).