Summary: The optimal load redistribution problem is solved in this paper for heterogeneous non-dedicated service grids in a decentralized way. A coordination policy is proposed to make networked servers reach their optimal generic task acceptance rates in order to minimize the average service time of all the generic tasks in a grid. Autonomous servers networked in the grid only need to coordinate with their neighbors iteratively, and their optimal generic acceptance rates are reached by task migration among them. The design scheme of the policy is introduced, and the convergence properties and the implementation aspects of the coordination system are discussed in detail in this paper. A set of computer simulations have been conducted, validating the effectiveness of the proposed approach.