Utilities, Natural Gas, Electricity, Energy, Energy Efficiency Northern Indiana Public Service Company (NIPSCO), with headquarters in Merrillville, Indiana, has proudly served the energy needs of northern Indiana for more than 100 years. As Indiana's largest natural gas distribution company, and the second largest electric distribution company, the NIPSCO serves approximately 810,000 natural gas and 460,000 electric customers across 32 counties. NIPSCO is one of NiSource's (NYSE: NI) seven regulated utility companies. NiSource is one of the largest fully-regulated utility companies in the United States, serving approximately 3.5 million natural gas customers and 500,000 electric customers across seven states through its local Columbia Gas and NIPSCO brands.