This paper presents a mixed integer nonlinear programming approach for solving The Transmission Network Expansion Planning (TNEP) problem through a hybrid genetic algorithm.The TNEP determines the set of new circuits required in an electrical power system to attend future energy demand at a minimum cost.In its classic version, it only considers as candidate solutions the addition of new lines and transformers.The main contribution of this work is the inclusion of nonconventional candidate solutions which include are repowering of existing circuits and shunt compensation.Also an AC modeling of the network that allows obtaining more realistic results has been considered.Results on the IEEE 24bus test system show the applicability and effectiveness of the proposed approach.