An approach is provided for cell selection or reselection in a multi-radio network environment involving at least two different radio access technologies. A service preference information which indicates service preferences for different radio access technologies can be set at a network element and be sent to at least one terminal device. At the terminal device, the service preference information is detected and a serving cell is selected based on the detected service preference information. Thereby, the network is capable of performing service-based control of cell selection or reselection of the terminal device upon initiating access for a certain service in an overlaid multi-RAT environment. This in turn enhances network utility, operation and performance.