Oklahoma’s chief legal official is calling on utility regulators there to dismiss a case brought by a subsidiary of American Electric Power (AEP) seeking pre-approval to recover its roughly 30% cost share of a $4.5bn wind and transmission line project in the state.

Last Friday, attorney general Mike Hunter through his public utility division filed a motion asking the Oklahoma Corporation Commission to issue an order rejecting the petition by Public Service Company of Oklahoma (PSO), citing multiple “failures” on its part.