Power producers Duke Energy Co and Entergy Corp reported lower second-quarter earnings Tuesday as the weak U.S. economy reduced electricity demand from their biggest industrial customers.

The worst U.S. recession in decades has forced many companies to curtail operations, lay off workers and cut costs in a bid to preserve cash, reducing the amount of electricity they use.

Even with new signs that the economy may be bottoming out, Duke, the fifth-largest U.S. utility owner by market value, said a survey of it customers indicated no near-term rebound.

As we look to the future, it's difficult to predict a resurgence, but we believe that it could be 2011 before we see recovery in our industrial usage, Lynn Good, Duke's chief financial officer, told a conference call.

Duke's second-quarter profit fell 21 percent to $276 million, or 21 cents per share. Excluding one-time items, earnings were 25 cents a share, beating the average Wall Street forecast by a penny, according to Reuters Estimates.

Entergy, which has delayed the proposed spin-off of five of its nuclear power plants into a separate company, posted a 16 percent drop in second-quarter profit to $226.8 million, or $1.14 per share. Excluding special items, earnings were $1.23 per share, 3 cents below the average Wall Street forecast.

ENTERGY NUKES WEAK

Entergy, which cut its 2009 profit forecast last month because of weaker power prices and financial impairments, was hurt in the second quarter by refueling and outages at its nuclear power plants.

We've taken great pride in meeting our goals over the years, and missing both -- missing the targets for both 2009 earnings and the time in closing the spinoff -- has been very disappointing to say the least, Chairman and Chief Executive J. Wayne Leonard said on a conference call. All I can say is we are committed to getting back on track and achieving our aspirations.

Also on Tuesday, utility holding company PPL Corp
posted lower-than-expected earnings and cuts its 2010 profit forecast, sending its shares down 11.5 percent to $30.06 at midday on the New York Stock Exchange.

Shares in Duke were off 9 cents at $15.48, while Entergy shares were down $2.58, or 3.2 percent, at $78.40.

Duke shares are up 0.5 percent so far this year while Entergy shares are off 4.6 percent. The broader Standard & Poor's utility index <.GSPU> is down about 1 percent.

(Reporting by Matt Daily; editing by John Wallace)