Hot summer sends Duke profits soaring

The company earned $670 million, or 51 cents per share, up from $109 million, or 8 cents per share, during the same period a year prior. Revenue rose to $3.95 billion from $3.4 billion.

Analysts polled by Thomson Reuters expected 42 cents per share on $3.74 billion in revenue.

Looking ahead, the company boosted its full-year profit outlook to between $1.40 and $1.45 per share, from $1.30 to $1.35 per share. Analysts expect $1.34 per share.

"The key to Duke Energy's outstanding third quarter was the ability of our employees and our fleet to meet customers' energy demands during the summer's unrelenting heat," said James E. Rogers, chairman, president and CEO, in a statement.