* GM shares fall; federal prosecutors open criminal probe -source
* Fuel-cell stocks tumble after short-seller note
* Copper prices fall to lowest since July 2010
* Men's Wearhouse to acquire Jos. A. Bank Clothiers
* Indexes off: Dow 0.4 pct, S&P 0.5 pct, Nasdaq 0.6 pct
NEW YORK, March 11 (Reuters) - U.S. stocks fell on Tuesday, with selling picking up late in the session, as investors cashed in some of the recent market gains, but the S&P 500 finished less than 1 percent away from a record high set last week.
Indexes had swung between gains and losses in the first half of the session, as the lack of major corporate earnings or market-affecting data kept trading directionless, but they closed near the day's lows.
Shares of retailers American Eagle and Urban Outfitters fell sharply after disappointing outlooks.
"We just hit highs on Friday so people have a lot of profits here. They're just taking some money off the table," said Frank Lesh, futures analyst and broker at FuturePath Trading LLC in Chicago. The selling "is orderly, there is no rush for the exits," he said.
The Dow Jones industrial average fell 67.43 points or 0.41 percent, to 16,351.25, the S&P 500 lost 9.54 points or 0.51 percent, to 1,867.63 and the Nasdaq Composite dropped 27.26 points or 0.63 percent, to 4,307.188.
Federal prosecutors in New York are examining whether General Motors is criminally liable for failing to properly disclose problems in some vehicles that were linked to 13 deaths and led to a recall last month, according to a source familiar with the investigation. GM shares fell 5.1 percent to $35.18.
Shares of fuel cell maker Plug Power plunged 41.5 percent to $6.03 after short-seller Citron Research said the fair value of the stock was 50 cents. Shares of other fuel cell makers fell, with Fuel Cell Energy down 16.5 percent to $3.28, Ballard Power Systems off 25.9 percent to $5.10 and Hydrogenics Corp down 14.7 percent.
Shares in the sector have been on a tear, with Plug Power up 940 percent since the end of October.
Urban Outfitters dropped 4.3 percent to $35.91 after it reported lower-than-expected quarterly sales and said it was "very cautious" on its current quarter. American Eagle Outfitters slumped 7.8 percent to $13.10 after it forecast earnings for the current quarter that were short of expectations.
The S&P retail index dropped 0.66 percent.
Men's Wearhouse said it would acquire rival Jos. A. Bank Clothiers for about $1.8 billion, ending a five-month saga that started with Jos. A. Bank offering to buy its larger menswear rival. Men's Wearhouse shares rose 4.7 percent to $57.14 and Jos. A. Bank added 3.9 percent to $64.22.
"M&A activity has been picking up, and it tends to offer a halo effect on sectors and subsectors involved," said Quincy Krosby, market strategist at Prudential Financial in Newark, New Jersey, pointing to broad support to the market of late coming from mergers and acquisitions.
Boyd Gaming Corp jumped 16.5 percent to $13.75 a day after hedge fund Elliott International disclosed a 4.99 percent stake in the gaming company.
Freeport-McMoRan Copper & Gold fell 2.1 percent, bringing the decline in the past four sessions to 9.4 percent. Copper prices on the London Metal Exchange hit their lowest level since July 2010 under pressure from rising inventories of the metal and slow demand.
Myriad Genetics Inc lost 8.3 percent to $34.60. The diagnostics company said a U.S. court denied a motion that would have stopped rival Ambry Genetics Corp from selling a similar version of Myriad's cancer test.
La Jolla Pharmaceutical Co surged 64.8 percent to $17.96 after the company said its lead experimental drug to treat chronic kidney disease met the main goal of improving kidney function in a mid-stage study.
About 6.9 billion shares traded in U.S. exchanges, according to the latest available data from BATS Global Markets, slightly above the 6.8 billion daily average so far this month.
Decliners outnumbered advancers by about 2 to 1 on the NYSE and on the Nasdaq more than 8 issues fell for every 3 that rose.