Most existing virtual network (VN) provisioning approaches assume a single administrative domain and therefore, VN deployments are limited to the geographic footprint of the substrate provider. To enable wide-area VN provisioning, network virtualization architectures need to address the intricacies of inter-domain aspects, i.e., how to provision VNs with limited control and knowledge of any aspect of the physical infrastructure. To this end, we present a framework for large-scale VN provisioning. We decompose VN provisioning into three steps to overcome the implications of limited information on resource discovery and allocation. We present a new resource selection algorithm with simultaneous node and link mapping to assign resources within each domain. We use a signaling protocol that integrates resource reservations for virtual link setup with Quality-of-Service guarantees. Our experimental results show that small VNs can be provisioned within a few seconds.