Future envisions universal and uninterrupted access to information owing to the widespread use of heterogeneous wireless technologies. The integration of heterogeneous wireless technologies and existence of multi-mode terminals enable users get associated to the best available networks according to user preferences over different application specific requirements, prices and network technologies. In this paper we present the user-centric network selection decision mechanism, where negotiation between users and network operators is carried out using game-theoretic approach. We model the utility functions of users and network operators in terms of offered prices and service quality. The proposed approach builds on IEEE 802.21standard. Session Initiation Protocol(SIP) and Mobile Internet Protocol (MIPv6) based flow management solutions are given, the later approach is implemented using OPNET modeller simulator. The performance of our approachis compared with Long-term contractual approach in termsof users throughput, users’ cost, operators’ revenue and call blocking probability.