Access control in enterprises is a key research area in the realm of Computer Security because of the unique needs of the target enterprise. As the enterprise typically has large user and resource pools, administering the access control based on any framework could in itself be a daunting task. This work presents X-GTRBAC Admin, an administration model that aims at enabling policy administration within a large enterprise. In particular, it simplifies the process of user-to-role and permission-to-role assignments, and thus allows decentralization of the policy administration tasks. Secondly, it also allows for specifying the domain of authority of the system administrators, and hence provides mechanism to distribute the administrative authority over multiple domains within the enterprise. The paper also illustrates the applicability of the administrative concepts presented in our framework for enterprise-wide access control. Categories and Subject Descriptors D.4.6 [Security and Protec...