ST. LOUIS (AP) -- Ameren Corp. posted lower second-quarter earnings on higher revenue as electric rates rose but customers used less power.

The utility on Thursday reported net income of $138 million on $1.78 billion in sales during the second quarter. That's down from net income of $152 million on $1.73 billion in revenue during the same period last year.

On a per share basis, the company earned 57 cents. It posted adjusted earnings of 59 cents. Analysts expected earnings of 62 cents on revenue of $1.75 billion, according to FactSet.

The company also incurred higher maintenance costs because of an unusually high number of storms in the company's service territory.

Ameren, based in St. Louis, serves 2.4 million electric customers and 900,000 natural gas customers in Missouri and Illinois.

Electric power use, measured by kilowatt-hours, fell 4 percent for the quarter, led by a 6 percent drop in residential power use. Power used by commercial customers such as office buildings and retail stores fell 3 percent. Factory use was flat.

The drop in power sales was offset by higher gas and electric rates that began taking effect last year.

Ameren's shares fell $1.54, or 5.3 percent, to $27.01.