Abstract--The worldwide trend for restructuring of electric industry including generation, transmission, and distribution sectors has caused dramatic changes in operation and planning procedures of the power system. Under restructured electricity market environment, identifying a minimum-cost plan under particular constraints is not sufficient any more; other aspects such as market efficiency and environmental concerns are of equal importance as the cost minimisation objective along with more uncertainties. In this context, network augmentation plays a vital role in providing a full competitive environment for market players. This paper presents a novel forward heuristic algorithm to select the most effective expansion options based on a set of sensitivity indices which takes in to account the construction cost and market efficiency. The proposed method has been applied on a 6- bus test system for verifying its effectiveness.