NEW YORK (AP) - Stocks are falling on Wall Street following reports that construction spending and manufacturing have weakened in the U.S.

The Dow Jones industrial average was down 86 points at 13,004 shortly before midday Tuesday. The broader S&P 500 index fell seven points to 1,399 and the Nasdaq composite fell 20 points to 3,047. The U.S. stock market was closed Monday for Labor Day.

Industrial and materials stocks fell the most. Heavy equipment maker Caterpillar was the weakest stock in the Dow average, slipping 3 percent, or $2.58, to $82.75.

The Commerce Department reported that U.S. construction spending fell by the most in a year in July. Another report delivered more gloomy news on the economy: the third straight month of contraction in U.S. manufacturing.