DTE Energy is a holding company. Co. is engaged in the generation, purchase, distribution and sale of electricity to customers in southeastern Michigan through its DTE Electric Company subsidiary, as well as in the purchase, storage, transportation, distribution and sale of natural gas throughout Michigan and the sale of storage and transportation capacity through its DTE Gas Company subsidiary. Co.'s non-utility operations are: gas storage and pipelines, which consists of natural gas pipeline, gathering, transportation, and storage businesses; power and industrial projects; and energy trading, which consists of energy marketing and trading operations.