Though a lot of research is reported on the transmission expansion planning (TEP), few have considered the impact of wind sources with varying penetration. Inadequate transmission capacities can result in spillage of the wind power. This has implications on loss of load and higher cost of generation. The proposed methodology formulates an integrated approach to TEP, which optimizes cost of new lines, spillage of wind power, loss of load and cost of generation. The resultant TEP problem is of the Mixed Integer Non Linear Programming (MINLP) type. Different scenarios are considered by varying the penetration levels resulting in different cases. The effect of growth in load demand is also considered. The formulation is tested using Garvers 6-Bus system and results are obtained using the Standard Branch and Bound (SBB) solver. As expected, optimum selection of new lines are able to reduce the spillage and cost of generation. The DCOPF results indicate the optimal schedule for the given load and wind generation data. The loss of load levels in different cases and corresponding cost of generation are reported for all cases. This approach can provide some insight to the decision maker to plan transmission expansion in presence of variable wind source and varying penetration level.