With the progress of ATM technologies and the wide use of LANs, private networks have become large-scale, consisting of various heterogeneous networks. Our goal is to manage ATM-LAN/WAN integrated networks in an end-to-end manner, where customers need not be aware of network heterogeneity. For this purpose, we propose a cooperative end-to-end connection management method that combines the management information on a customer's ATM-LANs and on the carrier's ATM-WANs interconnecting those ATM-LANs. Its main feature is the maximum use of customer network management services. It provides services of retrieving and controlling ATM-WAN management information. A prototype NMS confirms the feasibility of the proposed method.