Both technical and institutional changes suggest the need for more decentralized tools for estimation, control, and operation in wide area power system. The paper's aim is to coordinate the operation of several networks with purposes of networks' security preservation, based on decentralized strategies. The approach is formulated as an optimization problem, where the grid is split into control areas; each area is responsible for the optimal solution associated to its own region. To do this, one may exploit the fact that some systems may be weakly coupled and their interactions can be neglected, with little loss in the solution accuracy. Once the individual solutions are available, the corresponding settings are allocated to the corresponding equipment and a full power flow study is carried out to assure the steady state preservation. Results are exhibited on a 39-buses test power system.