NiSource Inc., an energy holding company, operates as a regulated natural gas and electric utility company in the United States.

It operates through two segments, Gas Distribution Operations and Electric Operations.

The company distributes natural gas to approximately 853,000 customers in northern Indiana, as well as approximately 2.4 million residential, commercial, and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, and Maryland.

It operates approximately 54,600 miles of distribution main pipelines, as well as associated individual customer service lines; and 1,000 miles of transmission main pipelines.

The company generates, transmits, and distributes electricity to approximately 483,000 customers in 20 counties in the northern part of Indiana, as well as engages in wholesale electric and transmission transactions.

It owns and operates coal-fired electric generating stations with a capacity of 722 megawatts (MW) in Wheatfield and 455 MW in Michigan City; combined cycle gas turbine with a capacity of 563 MW in West Terre Haute; natural gas generating units with a capacity of 155 MW in Wheatfield; hydro generating plants with a capacity of 9 MW in Carroll County and 7 MW in White County; and wind generating units with a capacity of 102 MW and 302 MW in White County, Indiana.

The company was formerly known as NIPSCO Industries, Inc. and changed its name to NiSource Inc. in April 1999.

NiSource Inc. was founded in 1847 and is headquartered in Merrillville, Indiana.