By November 1997 there was a published report stating that the company wished to acquire Central & South West Corp. HI declined to comment.

Its businesses included power generation and retail energy services in Texas newly deregulated electricity market.

On the wholesale side, Reliant owned, had an interest in, or leased 37 operating power generation facilities serving five regions of the United States.

[citation needed] In January 2007, the Texas electricity market became fully deregulated, and Reliant began to offer an array of products, flexible service options, and pricing arrangements to a variety of customers.

At this time, Reliant was the second largest mass market electricity provider in the state of Texas, with an annual revenue of $10.9 billion and more than 3,500 employees.

On April 11, 2010, RRI Energy and Atlanta-based Mirant Corp. announced an agreement to merge in a $1.6 billion all-stock deal, which created one of the largest independent power plant operators in the country.

The new company, named GenOn Energy, would be based in Houston but led by Mirant's Chairman and CEO Edward Muller until 2013.

New Jersey claims emissions of smog and acid rain components sulfur dioxide and nitrogen oxides from Reliant's Portland Generating Station in Northampton County, Pennsylvania, drift into its territory.

The lawsuit also claims that Reliant violated the federal Clean Air Act by modifying and operating the plant without required pollution control equipment and construction permits.