Diversified U.S. manufacturer SPX Corp slashed its 2009 profit forecast by about 18 percent, warning that it expects revenue to be weaker than forecast as a global downturn hurts demand for its products.

The company, which makes products ranging from cooling towers used in power plants to tools for repairing cars, said on Monday it now expects to report profit from continuing operations of $4.40 to $4.80 per share this year, down from a prior forecast of $5.40 to $5.80 per share.

Analysts had looked for profit of $5.11 per share, according to Reuters Estimates.

At the midpoint of those two ranges, that represents an 18 percent lowering of the forecast.

The Charlotte, North Carolina-based company looks for full year revenue to decline 12 percent to 16 percent, a deeper drop than its prior forecast of revenue flat to down 5 percent.

Demand in our short-cycle flow technology end markets has been lower than our expectations, said Chris Kearney, chief executive of SPX. Sales in our tools and diagnostics business have been lower than expected due to the continued stress being experienced by global vehicle manufacturers and their dealer service networks.

SPX said it expects to report first-quarter profit from continuing operations at the low end of its prior forecast of 75 cents to 85 cents per share.

Analysts, on average, had forecast first-quarter profit of 76 cents per share.

SPX shares fell 11.4 percent to $47.50 in premarket trading, down from a $53.63 close on the New York Stock Exchange.

(Reporting by Scott Malone, editing by Dave Zimmerman)