Mobility in WSNs can impact the overall network performances. The controlled mobility offers the possibility of relocating sensing resources to areas with more intensive activity and/or decreased sensor density. This paper presents a novel algorithm for sensor nodes relocation that achieves longer sensor network lifetime. The algorithm has distributed approach for sensors mobility, obtaining improved lifetime through maintaining energy balance. The algorithm assumes WSNs with cluster topology, and in this paper hexagonal clustering is considered. It allows relocation of sensor nodes between the neighboring cells based on predefined utility function and number of sensor nodes per cluster. The simulation results demonstrate the impact of the proposed mobility on extension of the WSN lifetime.