Energy Future Holdings Corporation is an electric utility company headquartered in Energy Plaza in Downtown Dallas, Texas, United States. The majority of the company's power generation is through coal and nuclear power plants. From 1998 to 2007, the company was known as TXU Corporation until its $45 billion leveraged buyout by Kohlberg Kravis Roberts, TPG Capital and Goldman Sachs Capital Partners. That purchase was the largest leveraged buyout in history. As of 2019, TXU Energy is a subsidiary of publicly traded Vistra Energy.
Enbridge Inc. is a Canadian multinational pipeline and energy company headquartered in Calgary, Alberta, Canada. Enbridge owns and operates pipelines throughout Canada and the United States, transporting crude oil, natural gas, and natural gas liquids, and also generates renewable energy. Enbridge's pipeline system is the longest in North America and the largest oil export pipeline network in the world. Its crude oil system consists of 28,661 kilometres of pipelines. Its 38,300 kilometre natural gas pipeline system connects multiple Canadian provinces, several US states, and the Gulf of Mexico. The company was formed by Imperial Oil in 1949 as the Interprovincial Pipe Line Company Limited to transport Alberta oil to refineries. Over time, it has grown through acquisition of other existing pipeline companies and the expansion of their projects.
The Ontario Energy Board is the provincial regulator of natural gas and electricity utilities in Ontario, Canada. This includes setting rates, and licensing all participants in the electricity sector including the Independent Electricity System Operator (IESO), generators, transmitters, distributors, wholesalers and electricity retailers, as well as natural gas marketers who sell to low volume customers.
Sonat, Inc., headquartered in Birmingham, Alabama, was a large Fortune 500 American energy holding company. The company was founded in 1928 and was listed on the New York Stock Exchange under the ticker symbol "SNT". Sonat was primarily involved in transmission and marketing natural gas and oil and gas exploration and production. The company was also involved in contract offshore drilling until 1995 when the offshore business became Transocean. In 1999 Sonat merged with El Paso Corporation. The company was headquartered in the AmSouth-Sonat Tower in downtown Birmingham.
National Grid plc is a British multinational electricity and gas utility company headquartered in London, England. Its principal activities are in the United Kingdom, where it owns and operates electricity and natural gas transmission networks, and in the Northeastern United States, where as well as operating transmission networks, the company produces and supplies electricity and gas, providing both to customers in New York and Massachusetts.
Public electricity suppliers (PES) were the fourteen electricity companies created in Great Britain when the electricity market in the United Kingdom was privatised following the Electricity Act 1989. The Utilities Act 2000 subsequently split these companies between distribution network operators and separate supply companies.
Sempra is a North American public utility holding company based in San Diego, California. The company is one of the largest utility holding companies in the United States with nearly 40 million consumers. Sempra's focus is on electric and natural gas infrastructure and its operating companies include: Southern California Gas Company (SoCalGas) and San Diego Gas & Electric (SDG&E) in Southern California; Oncor Electric Delivery Company in Texas; and Sempra Infrastructure, with offices in California.
SCANA Corporation was an American regulated electric and natural gas public utility. The company was based in Cayce, South Carolina, a suburb of Columbia, South Carolina. Following the Nukegate scandal, the company's stock fell and the company was in disrepair. In January 2019, SCANA was acquired by Dominion Energy. The corporate name SCANA was not an acronym, but was taken from the letters in South Carolina.
UGI Corporation is a natural gas and electric power distribution company headquartered in King of Prussia, Pennsylvania, with extensive operations in the United States and Europe.
Eastern Electricity plc was an electricity supply and distribution utility serving Eastern England, including East Anglia and part of Greater London. It was renamed Eastern Group under which name it was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index until it was acquired by Hanson plc in 1995, before being purchased by Texas Utilities in 1998.
The Gas and Fuel Corporation of Victoria (G&FC) was a government-owned monopoly supplier of household gas in Victoria, Australia. It was established in 1950 and took over two of the three main gas utilities in Melbourne – the Metropolitan Gas Company and the Brighton Gas Company. As part of the conversion to natural gas, in 1971 the corporation acquired the Geelong Gas Company, one of only two remaining private gas companies in Victoria at the time. The Ballarat Gas Company closed at the time. The G&FC was wound up in June 1995.
Southern Company Gas, formerly AGL Resources, is an American Fortune 500 energy services holding company headquartered in Atlanta, Georgia. The company's operations consist of natural gas distribution, wholesale services, retail operations, and midstream operations. Southern Company Gas is one of the largest natural gas distribution companies in the United States. The company serves approximately 4.5 million utility customers through its regulated distribution subsidiaries across four states. Southern Company Gas made the Fortune 500 list in 2015, Forbes 2000 in 2006, and is a member of the S&P 500 Index. In 2016, Southern Company acquired AGL Resources and renamed it Southern Company Gas.
Questar Corporation was a natural gas public utility based in Salt Lake City, Utah. In September 2016, the company was acquired by Dominion Resources.
Spectra Energy Corp, headquartered in Houston, Texas, operated in three key areas of the natural gas industry: transmission and storage, distribution, and gathering and processing. Spectra was formed in late 2006 from the spin-off from Duke Energy. Spectra owned the Texas Eastern Pipeline (TETCo), a major natural gas pipeline which brings gas from the Gulf of Mexico coast in Texas to the New York City area, which was one of the largest pipeline systems in the United States. Spectra also operated three oil pipelines. In February 2017, Spectra Energy merged into the Canadian company Enbridge.
Coastal Corporation was a diversified energy and petroleum products company headquartered at 9 Greenway Plaza in Greenway Plaza, Houston, Texas. The company was founded in 1955 by Oscar Wyatt and incorporated in 1955 as Coastal States Gas Producing Company. It merged with the El Paso Corporation in 2001. As of 1999, Coastal was a Fortune 500 company with 13,300 employees and annual revenues of $8.2 billion.
Énergir, formerly known as Gaz Métro, is an energy company with 520,000 customers in Quebec and the northeastern United States. It is the largest natural gas distribution company in Quebec, and, through subsidiaries, also produces electricity from wind. In the United States the company operates through subsidiaries in seventeen states, where it produces electricity from hydroelectric, wind and solar sources, in addition to being the leading electricity distributor and the sole natural gas distributor in Vermont.
Algonquin Power & Utilities Corp. is a Canadian renewable energy and regulated utility conglomerate with assets across North America. Algonquin actively invests in hydroelectric, wind and solar power facilities, and utility businesses, through its three operating subsidiaries: Bermuda Electric Light Company, Liberty Power and Liberty Utilities.
The US natural gas pipeline system is a complex system of pipelines that carries natural gas nationwide and for import and export for use by millions of people daily for their consumer and commercial needs. Across the country, there are more than 210 pipeline systems that total more than 305,000 miles of interstate and intrastate pipelines.
US$2.82 billion(2020) [1] 
US$824.1 million (2020) [2] 