Exelon’s (EXC) third-quarter net income grew 8.2% last quarter but the power company’s revenue widely missed analysts’ projections and it cut its full-year profit guidance.

Exelon posted adjusted-earnings of 96 cents for the third quarter, matching the Street’s view. However, the largest U.S. owner of nuclear power plants said its revenue fell 17% to $4.34 billion – significantly lower than analysts’ forecasts for $5.36 billion.

Looking ahead, Exelon narrowed its 2009 EPS guidance to $4 to $4.10 per share. That’s just under the Street’s expectations for EPS of $4.11 and below its earlier guidance for $4 to $4.30.

Exelon’s shares sank to $50.25 ahead of the opening bell, down from $50.84 at Thursday’s close. The power company’s stock has lagged well behind the broader markets, sinking almost 9% year-to-date.