Columbia Gas of Ohio is an investor-owned public utility that sells natural gas and provides gas transportation services to customers in Ohio. It is one of the largest natural gas utilities that serves more than 1 million residential, commercial and industrial customers in Ohio. The company administers the Customer CHOICE program, which offers customers the opportunity to reduce their energy costs by purchasing natural gas from nonutility suppliers. It serves more than 25,000 square miles in over 55 counties. Columbia Gas of Ohio maintains operations in the communities of Columbus, Toledo, Parma, Mansfield and Springfield in Ohio. It is one of the distribution companies of NiSource.