Southern Company, through its Southern Energy Inc. subsidiary, has reached a long-term agreement with The Dominion Companies to act as the luxury apartment developer’s energy provider and consultant.

Southern Company, the nation’s largest producer of electricity, will have the exclusive right to provide energy to all of Dominion’s properties, where Southern legally can provide such a service. Where Southern cannot supply energy, it will conduct negotiations on behalf of Dominion with its suppliers.

“We’ve been very happy with Southern’s ability to provide energy and energy-related services,” said Elliott Lewis, president of Dominion. “We want that level of service at all our communities.”

Southern and Dominion already have worked as partners at the Chatelaine Park apartment community in Duluth, Ga. The companies, working with other partners, have cooperated there in a pilot program to bring services to residents under a unified bill — services including electricity supply and energy management, cable and interactive television, Internet access, intrusion alarm systems, and long-distance phone service.

In addition to naming Southern as Dominion’s energy supplier, the agreement allows Southern to coordinate services similar to Chatelaine’s at communities of Dominion’s choosing. The Chatelaine pilot project has shown such services can save both the property owner and residents money.

“We see the Dominion relationship as the first example in the United States of innovative prices and products being developed specifically for residential consumers in anticipation of a choice environment,” said Bill Roth, Southern Energy’s director of marketing.

Dominion currently has 16 apartment communities completed or in development. Twelve are in Southern Company territory, with the others in the Carolinas or Tennessee. About 60 percent of Dominion residents are former homeowners who want luxury without the burden of maintenance. Dominion’s apartments offer details comparable to custom-built homes.

Atlanta-based Southern Company (NYSE: SO) is the parent firm of five electric utilities: Alabama Power, Georgia Power, Gulf Power, Mississippi Power and Savannah Electric. It also markets energy-related services and mobile radio services under the Southern name. Its Southern Energy Inc. subsidiary builds, owns and operates power production and delivery facilities and provides a broad range of services in the U.S. and international markets.

Southern Company’s common stock is one of the 20 most widely held corporate stocks in America.