Duke Energy Corp, the largest U.S. power company by market value, reported a 80% rise in quarterly profit on higher revenue from its rate-regulated utilities.

Net income attributable to Duke rose to $609 million, or 86 cents per share, in the second quarter ended June 30, from $339 million, or 48 cents per share, a year earlier.

The results a year earlier included a charge to write off investments in a failed Florida nuclear project and other one-time items.

Revenue from its regulated electric utilities increased nearly 7 percent to $5.17 billion in the latest quarter. (Reporting by Swetha Gopinath in Bangalore; Editing by Savio D'Souza)