David M. Ratcliffe, chairman, president and CEO of the Southern Co., announced Tuesday he will retire Dec. 1, and his successor will be Thomas A. Fanning, currently the companyâ¿¿s chief operating officer. On Aug. 1, Fanning, 53, will become president of Atlanta-based Southern Co. (NYSE: SO), and then he will become the companyâ¿¿s chairman and CEO on Dec. 1. â¿¿During his nearly 30-year career with Southern Co. and its subsidiaries, Tom has demonstrated the technical and financial capabilities and the strategic vision needed to guide this company during a period of unprecedented capital expansion and growth,â¿ Ratcliffe said in a news release. â¿¿Moreover, his leadership and team-building qualities will be crucial assets as he navigates a challenging, evolving energy landscape.â¿ Ratcliffe has been one of the top civic leaders in the state, having served as chairman of the Georgia Chamber of Commerce, the Georgia Research Alliance and the Commerce Club. Fanning joined the Southern Co. in 1980 as a financial analyst. Since then, he has held officer-level positions in the areas of finance, strategy, international business development and technology. Prior to becoming executive vice president and COO in 2008, he was Southern Co.â¿¿s chief financial officer. Fanning also served as president and CEO of the companyâ¿¿s Florida subsidiary, Gulf Power, and CFO of both Georgia Power and Mississippi Power. Ratcliffe became CEO of the Southern Co. in 2004, succeeding Allen Franklin. Both Ratcliffe and Franklin had served as president of Southern Co.â¿¿s largest subsidiary -- Georgia Power -- before becoming CEO of the parent company. The succession pattern this time around is a bit different, partly because Georgia Power CEO Michael Garrett, 60, and Ratcliffe, 61, are so close in age. Ratcliffe also made several other announcements that give some indication on the future leadership of not only Southern Co., but its subsidiaries.