Dussmann, Wisag Service Holding, Bilfinger Berger Facility Services/HSG, Hochtief Facility Management, Piepenbrock Dienstleistungsgruppe, Voith Industrial Services Holding, Klüh Service Management, M+W Zander D.I.B. Facility Management, Zehnacker Facility Management Services, Gegenbauer.
Quelle: "Facility Management", Ausgabe 3/2007