The Atlanta company, which provides electricity to 4.4 million customers in the Southeast, reported earnings of $368 million, or 42 cents a share, for the first three months of the year. That compares with $422 million, or 50 cents a share, in the same part of 2011.
Revenue fell 10.2 percent to $3.6 billion in the quarter.
The results fell short of analysts’ expectations of 45 cents per share on revenue of $3.72 billion, according to FactSet.
Southern Co. blamed the mild winter on a decline in retail and wholesale electricity demand. Total energy sales to customers fell by 7.3 percent in the first quarter. Residential and commercial energy sales fell by 13.7 percent and 3.1 percent, respectively. Industrial energy sales increased 1.9 percent.
Shares fell 34 cents to $41.53 in afternoon trading.