In this paper, we consider the multiple sinks placement problem in large-scale wireless sensor networks (WSN). The objective is to determine optimal sinks' positions that maximize the network lifetime by reducing energy consumption related to data transmissions from sensor nodes to different sinks. Balanced graph partitioning techniques are used to split the entire WSN into connected sub-networks. Smaller subnetworks are created, having similar characteristics and where energy consumption can be optimized independently but in the same way. Therefore, different approaches and mechanisms that enhance the network lifetime in small-size WSN can be deployed inside each sub-network. In this paper, we propose a simple and efficient approach for the placement of multiple sinks within large-scale WSNs. Performance results show that the proposed technique significantly enhances the network lifetime