Market equilibrium models with conjectural variations have been used to planning generation in the medium term during the last years. When different countries or big markets try to function as unique markets equilibrium models encounter the problem of how to model the conjectures of the agents depending on the congestion of the different transmission network. This paper proposes a methodology to reduce the number of possible scenarios in the network. Then, a case of study applying the methodology to the Central Western Europe countries is presented.