US STOCKS-Wall St flat after Nasdaq tops 4,000; Wal-Mart at record

* Oil falls after Iran deal, energy shares pressured

* Facebook (NasdaqGS: FB - news) , Yelp (NYSE: YELP - news) shares down

* Dow up 0.02 pct; S&P off 0.2 pct; Nasdaq up 0.04 pct

By Luke Swiderski

NEW YORK, Nov 25 (Reuters) - U.S. stocks retreated to almost unchanged in light trading late Monday afternoon following the Nasdaq Composite's climb above 4,000 for the first time in 13 years.

Wal-Mart Stores Inc rose 0.6 percent to $80.31. At one point, the stock touched an all-time high of $80.57 after the company said it chose its next chief executive.

The major U.S. stock indexes were overall little changed in what is expected to be a quiet week ahead of the U.S. Thanksgiving holiday on Thursday.

"Retailers are taking focus this week. Black Friday is coming up, so there will be obviously some positioning ahead," said Dennis Dick, proprietary trader at Bright Trading LLC in Las Vegas, referring to the hectic day just after Thanksgiving that's regarded as the start of the holiday shopping season.

The agreement between world powers and Iran to partially curb Iran's nuclear program was seen as bolstering positive sentiment, even though it may not increase Iran's oil exports. Light (Other OTC: LGSXY - news) sweet U.S. crude oil fell almost 1 percent to $94.09 a barrel.

The S&P energy index fell 0.9 percent.

Despite the pressure on the energy sector, the deal with Iran was viewed as having positive benefits for the market at large.

"Less tension in the Middle East is always a positive, and any drop in gas prices will essentially act as a tax break for consumers going into the holiday shopping season," said Jeff Duncan, chief executive of Duncan Financial Management in St. Louis. "This is a real benefit for the economy."

Notable social media stocks fell, with Facebook breaking through a technical support level at $45.80. Facebook shares were down 3.2 percent at $44.73. Yelp shares fell 6.9 percent to $58.07. Twitter (NYSE: TWTR - news) shares lost 4.5 percent to $39.16.

The Dow Jones industrial average rose 3.11 points or 0.02 percent, to 16,067.99. The S&P 500 slipped 2.73 points or 0.15 percent, to 1,802.03. The Nasdaq Composite added 1.69 points or 0.04 percent, to 3,993.41, after earlier touching an intraday high at 4,007.09.

The market could still go higher, some analysts said, even though the S&P 500 is up 26.5 percent for the year and the Dow has risen seven weeks in a row.

"Not surprisingly, many investors are asking whether this sets us up for some type of pullback. In our view, the answer is a resounding 'No.' While these results are excellent, especially in the context of weak economic and earnings growth, they are hardly out of the ordinary," said Jonathan Golub, chief U.S. market strategist at RBC Capital Markets in New York.