Duke Energy (DUK) more than doubled its first-quarter profit and surpassed top-line Wall Street expectations on Friday, fueled by the integration of newly-acquired Progress Energy. 

Charlotte, N.C.-based Duke closed on its $14 billion purchase of Progress last summer in what has created the largest U.S. power company. The acquisition helped nearly double Duke’s U.S. franchised electric and gas business income to $656 million from $344 million in 2012.

Duke also benefited from favorable weather and revised customer rates, partially offsetting softness in its commercial power and international energy segments.

The energy giant reported net income of $634 million, or 89 cents a share, compared with a year-earlier profit of $295 million, or 66 cents. Excluding one-time items, Duke said it earned $1.02 a share, missing average analyst estimates in a Thomson Reuters poll by two pennies.

Revenue for the three months ended March 31 was $5.9 billion, up from $3.63 billion a year ago, trumping the Street’s view of $5.74 billion.

"We're 10 months into the merger with Progress Energy and we are pleased with the pace of our integration efforts,” said Duke CEO Jim Rogers. “We are clearly on track to achieve our merger commitments, providing benefits for both customers and investors."

Moving forward with the acquisition, Rogers said Duke will focus on safety as it continues to pursue near-term priorities, including the conclusion of regulated rate cases in the Carolinas and Ohio. It is also finalizing “major construction projects” to further diversify its pipeline.

Duke affirmed its fiscal 2013 profit view in the range of $4.20 to $4.45 a share, bracketing the consensus view of $4.33 a share.

Shares of Duke edged slightly higher in Friday morning trade to $75.47.

Follow Jennifer Booton on Twitter at @Jbooton