Four subsidiaries – but excluding exchange manufacturer Italtel SpA – of Italian state telecommunications holding company STET SpA have agreed to collaborate with Telefonica de Espana SA in their respective fields of interest: the four are the Italian phone service operator Societa Italiana per l’Esercizio delle Telecommunicazioni SpA; international telephone operator Italcable SpA, its satellite operations subsidiary Telespazio SpA, and its phone book arm Seat SpA.