Integrating Mobile ad hoc networks (MANET) to the Internet is a stimulating field in heterogeneous networks which comprises challenging issues. The Internet connectivity is provided by gateway nodes which are the interface between MANET and the Internet. The gateway selection and load balancing are considered as one of the fundamental challenging issues which are addressed separately in existing approaches for integrated Internet MANET. In the proposed work a novel Load-Sensitive Optimized Gateway Selection (LSOGS) has been implemented that satisfies the QoS-ensured services to all mobile nodes. The gateway deployment is based on coverage capacity to distance ratio and breadth-first search technique. The load balancing is performed by shifting operation when the load on any particular gateway exceeds its throughput capacity threshold. Lastly, the effectiveness of proposed algorithm has been evaluated by extensive simulation which shows the effectiveness of the proposed approach.