Resource management in first network based on service within second network

A method and corresponding system to help manage resources in a wireless communication system. When a first access network has allocated a resource for use in serving a UE and the UE has then transitioned from being served by the first access network to being served by a second access network, a determination may be made that (i) the UE has then moved into particular coverage of the second access network and (ii) the first access network does not have a coverage area that corresponds with that particular coverage area of the second access network. In response, the first access network may then release the resource that it had allocated for use in serving the UE. In a scenario where the first access is configured to normally release the resource upon expiration of a resource-release timer, the release in response to the determination may advantageously occur before the timer expires.