Three big energy companies operating in the Carolinas Tuesday reported plans to form a regional transmission organization with 22,000 miles of transmission lines and to be named GridSouth. CP&L Energy Inc., Duke Energy Corp., and SCANA Corp. said the proposal will be filed with the Federal Energy Regulatory Commission by October 16 and will be consistent with FERC's intent to have all utilities in the country operating in regional transmission organizations by Dec. 15, 2001.