ATLANTA (AP) - Southern Co. is reporting a 52 percent slump in second-quarter earnings due to cost overruns at a coal-fired power plant under construction in Mississippi.

ATLANTA (AP) Southern Co. is reporting a 52 percent slump in second-quarter earnings due to cost overruns at a coal-fired power plant under construction in Mississippi.

Earnings fell to $297 million for the three-month period ending in June, down from $623 million a year ago.

The Atlanta utility company released its quarterly earnings Wednesday after announcing an estimated $278 million after-tax write-off for larger-than-expected building costs at the power plant.

The company reported earnings of 34 cents per share, or 66 cents per share with one-time costs removed. That's still a couple cents shy of Wall Street projections, and company shares dipped in premarket trading.

Subsidiary Mississippi Power is reviewing its construction costs and has cautioned that those expenses could still rise.