American Electric Power (AEP) posted a 3% increase in second-quarter profit and flat sales on Friday as the utility tightened expenses and benefited from warm weather that lifted air conditioner usage. 

The Columbus, Ohio-based utility earned $362 million, or 75 cents a share, in its latest reporting period, compared with a year-earlier $352 million, or 73 cents.

Excluding one-time items, American Electric earned 77 cents, ahead of average analyst estimates of 71 cents in a Thomson Reuters poll.

Revenue for the three months ended June 30 was $3.6 billion, unchanged from a year ago and slightly topping the Street’s view of $3.57 billion.

“We had solid financial performance in the second quarter, driven by warmer than normal weather and our continued disciplined approach to controlling costs," American Electric CEO Nicholas Akins said in a statement.

The economy in the utility’s service territories has “shown some signs of improvement,” Akins said, with growth in western states outpacing that in its eastern markets. The gains were led by utility operations, which saw earnings climb 4% to $364 million.

Earnings were partially offset by the generating and marketing group, which swung to a loss of $5 million in the second quarter from a profit of $11 million in the 2011 period.  

Near the end of the period on June 29, a powerful storm swept through the Ohio area causing “considerable damage” and leaving more than 1.4 million customers in five states without power.

American Electric, which called that an “unprecedented outage number,” said the costs and lost revenue associated with the storm will be reflected in third-quarter results.

While American Electric's 2012 earnings guidance remains suspended due to ongoing Ohio regulatory proceedings, Akins said the company will face challenges in the remainder of the year, including customer switching in Ohio.

Shares of American Electric touched a 52-week high Friday morning before retreating with the broader market around noon New York time.

Follow Jennifer Booton on Twitter at @Jbooton