Ohio utility regulators have rejected an American Electric Power proposal to guarantee profitability from two of its aging coal plants. The Public Utilities Commission of Ohio ruled Wednesday that the plan was legal but it would not benefit customers. Commissioners declined to authorize a plan to cover the costs of generating electricity from the company's share of the Ohio Valley Electric Corporation, which includes which includes power plants in southeastern Ohio and southeastern Indiana. AEP filed the plan in December 2013. National environmental groups had urged regulators to reject the coal-plant idea, arguing that it was a bailout.