Power tool maker Stanley Black & Decker Inc. cut its 2013 profit forecast due to the U.S. government spending cuts and shutdown and slower-than-expected margin expansion in its security business.

Stanley Black & Decker shares fell 9 percent to $81.25 in trading before the bell on Wednesday.

The company reduced its full-year adjusted earnings forecast to $4.90-$5 per share from $5.40-$5.65.

Stanley Black & Decker said the cut mainly reflected margin pressure in its security business but was also due to the uncertainty created by the U.S. government's sequestration and shutdown and its impact on business, consumer confidence and spending.

"We really believe the U.S. government sequestration and shutdown has had a modest impact in Q3 on us and will have a slightly more significant impact on us in Q4," Chief Financial Officer Donald Allan said on a conference call with analysts.

The company reported a better-than-expected 44 percent rise in third-quarter net profit.