HOUSTON, Jan 29 (Reuters) - Texas utility regulators on Thursday awarded nine companies rights to build $5 billion in new electric transmission lines to move power from windy areas to big cities like Dallas and San Antonio, a move aimed at doubling renewable energy supplies. Dallas-based Oncor, the state's largest power company, American Electric Power's (AEP.N) joint venture Electric Transmission Texas and Sharyland Utilities, along with affiliates of FPL Group (FPL.N), Spanish-based Isolux Corsan and LS Power Group were awarded major portions of the grid expansion, which will add as much as 2,900 miles of new power lines. "We have...