FPL Group Inc.'s (FPL) third-quarter profit fell 31% amid weak electricity demand and prior-year mark-to-market gains, falling short of Wall Street estimates.

The company also lowered its 2009 earnings forecast to $4.10 a share to $4.20 a share from its July boosted forecast of $4.20 to $4.40 amid disappointing Texas gas generation contributions and lower-than-expected wind resources.

FPL Group also cut its 2010 earnings outlook to $4.25 a share to $4.85 a share from its boosted July view for $4.65 to $5.05.

Chairman and Chief Executive Lew Hay said Tuesday the company's generating business continued to grow while its Florida Power & Light Co. utility continues to be challenged by the economic downturn.

Slumping demand for electricity has hurt generators and utilities in recent quarters. FPL's electric utility serves customers in one of the states hardest hit by the economic downturn. Still, the utility is poised to expand its nuclear generating operations and NextEra generating unit is adding wind projects.

FPL reported a profit of $533 million, or $1.31 a share, down from $774 million, or $1.92 a share, a year earlier. Excluding items such as hedging gains and losses, earnings rose to $1.38 from $1.25.

Revenue decreased 17% to $4.47 billion.

Analysts polled by Thomson Reuters most recently forecast earnings of $1.41 on revenue of $4.96 billion.

At its regulated electric utility, earnings fell 2.5%. Total retail volume edged up 0.4%, amid warmer-than usual weather. The utility continued to lose customers, but at a slower pace, the company said for a decline of 9,000.

At its wholesale electricity generating business, earnings fell 52%, but excluding items, were up 21% amid its growing wind business.

Shares closed Monday at $52.13 and didn't trade premarket.

 
   -By Tess Stynes, Dow Jones Newswires; 212-416-2481; Tess.Stynes@dowjones.com;