Julie Edwards

Southern Union Co. engages in gathering, processing, transportation, storage and distribution of natural gas in the United States. The firm operates through three reportable segments: transportation and storage, gathering and processing, and distribution. The company was founded by George Lindemann in 1929 and is headquartered in Houston, TX.

ONEOK Partners LP engages in gathering, processing, storage, and transportation of natural gas. The company was founded in 1993 and is headquartered in Tulsa, OK.

Eagle Geophysical, Inc. operates as an international oilfield service company, which engaged in the acquisition of seismic information, with a specialization in the acquisition of definition three-dimensional seismic data. The company was founded in 1993 and is headquartered in Houston, TX.

NATCO Group, Inc. provides equipment technology for oil & gas production and processing. Its services include construction & maintenance, manufacturing, operating & leasing engineer equipment and training. The company also provides equipment solutions including oil treating, separation, gas conditioning, water quality, measurement systems and automation & controls. NATCO Group was founded in 1926 and is headquartered in Houston, TX.

Frontier Oil Corp. is an energy company, which is engaged in crude oil refining and wholesale marketing of refined petroleum products. The company operates refineries in Cheyenne, Wyoming and El Dorado, Kansas. Frontier Oil purchases crude oil to be refined and markets the refined petroleum products produced, including various grades of gasoline, diesel fuel, jet fuel, asphalt, chemicals and petroleum coke. The Cheyenne Refinery has a permitted crude oil capacity of 52,000 bpd and markets its refined products primarily in the Eastern slope of the Rocky Mountain region, which encompasses Eastern Colorado, Eastern Wyoming and Western Nebraska. It has a coking unit, which allows the refinery to process heavy crude oil for use as a feedstock. The El Dorado Refinery is in the Plains States and the Rocky Mountain region with crude oil capacity of 135,000 bpd. It markets gasoline and diesel in Denver and throughout the Plains States. Frontier Oil also owns Ethanol Management Co., a products terminal and blending facility located near Denver, Colorado. The company was founded in 1949 and is headquartered in Houston, TX.

Noble Corp. Plc engages in the provision offshore drilling services for oil and gas industry. It focuses on a balanced fleet of floating and jackup rigs and the deployment of drilling rigs in oil and gas basins around the world. The company was founded by Lloyd Noble and Art Olson in 1921 and is headquartered in Sugar Land, TX.

Panhandle Energy Cos. owns and operates natural gas pipelines. The company was founded in 1929 and is headquartered in Houston, TX.