In a competitive power market, the elastic demand for electrical energy transmission is viewed as a prime competitor of generator. Remote generators are needed for transmission to compete with local generators. The value of the transmission is based on the difference of Locational Marginal Price (LMP) of the generators across the network. To maintain the well operation of power market, LMPs which provide the price sensitivity is calculated at every bus. The revenue collected by the transmission owners is a convex quadratic function of the amount of power transmitted. This revenue provides a sound impact on investment perspective for setting the price that producers and customers should pay for the network. In this paper for a three bus system, the LMPs are calculated at the buses and a demand function for the transmission has been modeled which computes the maximum revenue for the optimal transmission capacity in the syste.