CenterPoint Energy, Inc. is an American Fortune 500 electric and natural gas utility serving several markets in the American states of Arkansas, Indiana, Louisiana, Minnesota, Mississippi, Oklahoma, and Texas. It was formerly known as Reliant Energy , NorAm Energy, Houston Industries, and HL&P. The company is headquartered in the CenterPoint Energy Tower at 1111 Louisiana Street in Downtown Houston. Some of its notable subscribers include Retail Electric Providers , such as NRG Energy, Champion Energy, Eligo Energy, Dynowatt, Ambit Energy, Texas Power, Bounce Energy, MXenergy, Direct Energy, Stream Energy, First Texas Energy Corporation, Gexa Energy, Cirro Energy, and Kona Energy. When the state of Texas deregulated the electricity market, the former Houston Lighting & Power was split into several companies. In 2003 HL&P was split into Reliant Energy, Texas Genco, and CenterPoint Energy.