Utility companies provide natural gas, electricity, water, sewage, and other basic necessities for both residential and commercial properties. While many companies in the utilities sector make a profit, they are typically heavily regulated by public authorities. Utility companies range from large businesses providing a spectrum of services to specialized, niche companies focusing on wind energy and other services.

These are the 10 biggest utility companies by 12-month trailing (TTM) revenue. This list is limited to companies that are publicly traded in the U.S. or Canada, either directly or through ADRs. Some companies outside the U.S. report profits semi-annually instead of quarterly, so the 12-month trailing data may be older than it is for companies that report quarterly. Data is courtesy of YCharts.com. All figures are as of August 3, 2020.

Some of the stocks below are only traded over-the-counter (OTC) in the U.S., not on exchanges. Trading OTC stocks often carries higher trading costs than trading stocks on exchanges. This can lower or even outweigh potential returns.

#1 Électricité de France SA (ECIFY)

  • Revenue (TTM): $76.8 billion
  • Net Income (TTM): $2.2 billion
  • Market Cap: $30.2 billion
  • 1-Year Trailing Total Return: -17.7%
  • Exchange: OTC

French state-owned Électricité de France SA (EDF) provides services such as power generation, transmission, distribution, and trading. As a major provider of power in France as well as elsewhere in the world, the company is involved in every aspect of the electricity industry. The company's production is currently 90% free from carbon dioxide emissions.

#2 Enel SpA (ENLAY)

  • Revenue (TTM): $67.6 billion
  • Net Income (TTM): $2.4 billion
  • Market Cap: $92.2 billion
  • 1-Year Trailing Total Return: 39.5%
  • Exchange: OTC

Based in Rome, Enel SpA is a multinational power company and a leading integrated player in the world’s power and gas markets, with a presence in 32 countries and a focus on Europe and Latin America. More than half of Enel's electricity production is from thermoelectric, nuclear, geothermal, wind, solar PV, and other renewable sources.

#3 Engie (ENGIY)

  • Revenue (TTM): $67.0 billion
  • Net Income (TTM): $1.1 billion
  • Market Cap: $32.1 billion
  • 1-Year Trailing Total Return: -13.0%
  • Exchange: OTC

Engie is a French multinational utility providing a broad spectrum of energy and environment services to customers in more than 70 countries. Previously known as GDF Suez, Engie has operations in electricity generation and distribution, natural gas, and renewable energy. The name change reflects the company’s departure from the state-owned nationalized gas monopoly.

#4 Tokyo Electric Power Co. Holdings (TKECY)

  • Revenue (TTM): $57.4 billion
  • Net Income (TTM): $0.5 billion
  • Market Cap: $4.4 billion
  • 1-Year Trailing Total Return: -40.9%
  • Exchange: OTC

Tokyo Electric Power Co. generates and distributes electricity through the Tokyo area and several other regions in Japan. An integrated utilities company, the firm utilizes hydroelectric, nuclear, and thermal power sources.

#5 E.ON SE (EONGY)

  • Revenue (TTM): $55.1 billion
  • Net Income (TTM): $0.9 billion
  • Market Cap: $30.3 billion
  • 1-Year Trailing Total Return: 22.8%
  • Exchange: OTC

Germany-based E.ON is an international energy supplier with operations across Europe. The company's focus is on power and gas distribution, while it also operates a customer solutions branch which is focused on energy sales, infrastructure, and growth businesses. E.ON's biggest markets are Germany and Sweden.

#6 Korea Electric Power Corp. (KEP)

  • Revenue (TTM): $49.4 billion
  • Net Income (TTM): -$1.3 billion
  • Market Cap: $10.1 billion
  • 1-Year Trailing Total Return: -33.3%
  • Exchange: New York Stock Exchange

South Korea's largest electric utility, Korea Electric Power Corp. generates and distributes electricity for a variety of residential and business uses. The company operates nuclear, thermal, and hydroelectric power units.

#7 Iberdrola SA (IBDRY)

  • Revenue (TTM): $38.3 billion
  • Net Income (TTM): $4.0 billion
  • Market Cap: $78.9 billion
  • 1-Year Trailing Total Return: 39.9%
  • Exchange: OTC

Iberdrola SA is a Spanish multinational electric utility with operations in the U.S., U.K., Spain, Portugal, and throughout Latin America. Among the company's subsidiaries are Scottish Power, Iberdrola USA, and Elektro (Brazil).

#8 Exelon Corp. (EXC)

  • Revenue (TTM): $33.7 billion
  • Net Income (TTM): $2.6 billion
  • Market Cap: $37.6 billion
  • 1-Year Trailing Total Return: -11.3%
  • Exchange: NASDAQ

Exelon Corp. operates as a utility services holding company serving millions of customers in Pennsylvania, Illinois, and several other areas of the U.S. The U.S. company is one of the largest domestic power generators, with power capacity generated by nuclear, gas, wind, hydroelectric, and solar stations.

#9 Kansai Electric Power Co. Inc (KAEPY)

  • Revenue (TTM): $29.3 billion
  • Net Income (TTM): $1.2 billion
  • Market Cap: $8.2 billion
  • 1-Year Trailing Total Return: -22.4%
  • Exchange: OTC

Kansai Electric Power Co. provides electricity to customers in Osaka and the surrounding Kansai region in Japan. The company builds and maintains electric power facilities and utilizes thermal, geothermal, nuclear, and hydroelectric power sources.

#10 Centrica PLC (CPYYY)

  • Revenue (TTM): $27.6 billion
  • Net Income (TTM): -$0.8 billion
  • Market Cap: $3.6 billion
  • 1-Year Trailing Total Return: -33.0%
  • Exchange: OTC

British multinational Centrica provides energy services to 25 million consumer accounts. Centrica primarily supplies electricity and gas to customers across the U.K. and elsewhere in Europe as well as in the U.S.