* Data on manufacturing and construction spending point to growth
* Forest Labs rallies after comments; 3M falls after downgrade
* Black Friday holiday sales dip on discounts
* Dow off 0.5 pct, S&P 500 down 0.3 pct, Nasdaq off 0.4 pct
By Ryan Vlastelica
NEW YORK, Dec 2 (Reuters) - U.S. stocks closed lower on Monday, with investors unable to find new reasons to keep pushing shares higher after eight straight weeks of gains, while the mining sector slid alongside sharp drops in precious metals prices.
The major U.S. stock indexes hovered near break-even levels for much of the day after some encouraging economic data limited early losses, but turned lower in the last hour of the trading day.
Equities have rallied in recent weeks on expectations of continued stimulus from the Federal Reserve. The S&P 500 has risen for eight straight weeks, its longest run since a nine-week climb between November 2003 and January 2004, putting its yearly gain at nearly 27 percent. Both the Dow and the S&P 500 have hit repeated all-time highs this year.
"We're not expecting a severe pullback, but we're not jumping into the market with both feet, given how far we've come, and that there are no real catalysts," said John Norris, managing director of wealth management with Oakworth Capital Bank in Birmingham, Alabama.
The Institute for Supply Management said its index of national factory activity rose in November to its best showing since April 2011, while the pace of hiring in the sector also accelerated. In addition, construction spending increased 0.8 percent in October, the highest since May 2009.
Mining companies' shares fell in sync with a slide in precious metal prices. Gold dropped 2.6 percent. Silver tumbled 4.2 percent.
Hecla Mining Co lost 6.1 percent to $2.77 while U.S. shares of Silvercorp Metals sank 5.1 percent to $2.41. Freeport-McMoRan Copper & Gold Inc fell 1.2 percent to $34.26.
The Dow Jones industrial average dropped 77.64 points, or 0.48 percent, to end at 16,008.77. The Standard & Poor's 500 Index declined 4.91 points, or 0.27 percent, to 1,800.90. The Nasdaq Composite Index fell 14.63 points, or 0.36 percent, to close at 4,045.26.
Dow component 3M Co fell 4.4 percent to $127.68 after Morgan Stanley downgraded the stock to "underweight" from "equal weight."
On the upside, Forest Laboratories Inc jumped 9.8 percent to $56.32 as the S&P 500's biggest percentage gainer after the company said it plans to buy rights to a new schizophrenia treatment from Merck & Co and cut annual operating costs by $500 million in fiscal 2016.
Retailers will stay in focus as the holiday shopping season ramps up. Heavy discounting took a toll on U.S. retail sales during the Thanksgiving weekend as shoppers spent almost 3 percent less than they did a year earlier, according to an industry group.
"I'm not agonizing about the Black Friday numbers," Norris said. "There's still a lot of time before the season ends, and it should be stronger than last year since the market has been so good, and people have more money to spend."
The S&P retail sector index fell 0.7 percent.
About 70 percent of companies traded on both the New York Stock Exchange and Nasdaq closed lower.