Diversified manufacturer Minnesota Mining & Manufacturing Co. on Monday reported a 21 percent decline in third-quarter earnings and said fourth-quarter results will fall at the low end of analysts' estimates as the slowing U.S. economy hurt sales. 

The maker of products ranging from Post-It notes and Scotch-brand tape to industrial adhesives and medical software said net income, including a charge for previously announced job cuts, fell to $394 million, or $1 a share, from $499 million, or $1.25 a share, a year earlier. 

Excluding the $43 million charge, earnings were $437 million, or $1.10 a share. Analysts had expected a profit of $1.05 to $1.12 a share, with an average estimate of $1.09, according to data tracker Thomson Financial/First Call. 

Sales fell 7.1 percent to $3.97 billion from $4.25 billion. 

The company said it expects to earn 95 cents to $1.05 in the fourth quarter before nonrecurring items. Analysts' estimates range from 95 cents to $1.13 a share, for an average of $1.05, according to First Call. 

``Although the economic outlook remains uncertain, we are focused on making the fundamental changes necessary to improve our competitive advantage via higher growth rates, increased productivity and improved asset turns,'' Chief Executive James McNerney said in a statement. 

In the third quarter, 3M said U.S. sales declined 6.7 percent to $1.92 billion. While unit volume increased in the health-care and transportation, graphics and safety segments, softness in most areas of the U.S. economy held back overall growth. 

International sales fell 7.5 percent to $2.05 billion. Volumes decreased 2.3 percent and selling prices were flat. Currency translations trimmed 5.2 percent, primarily due to weakness in Asia and Brazil. 

On a worldwide basis, the strong U.S. dollar reduced sales by 2.7 percent. 

3M, which had announced plans in April to cut 5,000 jobs, or 7 percent of its total, said selling, general and administrative costs fell almost 9 percent in the third quarter.