American Electric Power Company, Inc. (AEP) is a public utility holding company that owns, directly or indirectly, all of the outstanding common stock of its public utility subsidiaries and varying percentages of other subsidiaries. The Company's segments include Vertically Integrated Utilities, Transmission and Distribution Utilities, AEP Transmission Holdco, and Generation & Marketing. AEP's vertically integrated utility operations are engaged in the generation, transmission and distribution of electricity for sale to retail and wholesale customers. Transmission and Distribution Utilities segment consists of the transmission and distribution of electricity for sale to retail and wholesale customers. AEP Transmission Holdco develops, constructs and operates transmission facilities. Generation & Marketing segment's subsidiaries consist of nonutility generating assets, a wholesale energy trading and marketing business and a retail supply and energy management business.