* Europe's leaders at odds before summit
* In win for Apple, judge halts U.S. sales of Samsung tablet
* Analysts cautiously optimistic on Facebook
* Futures: Dow off 1 pt; S&P, Nasdaq up less than 1 pt
NEW YORK, June 27 (Reuters) - Wall Street was set to open flat on Wednesday as upbeat U.S. data was offset by concerns over slowing economic growth and expectations that another meeting of European leaders would do little to solve the region's debt crisis.
Demand for long-lasting U.S. manufactured goods rose sharply more than expected in May and a gauge of business spending plans increased, but decelerating global growth suggests the momentum might not be sustained.
Durable goods data "was better than expected, which is surprising to see since recent economic reports have been less positive. I'm still concerned we'll see a third summer of an economic deceleration," said David Carter, chief investment officer at Lenox Wealth Advisors in New York."
"While this is an important number, news out of Europe is still dominating equity markets."
Few anticipate anything concrete to emerge from the two-day European Union meeting that kicks off Thursday after German Chancellor Angela Merkel said debt sharing, an idea backed by France, Italy and Spain, would not happen in her lifetime.
"This is like a slow motion car accident occurring over there and the market has certainly set this into prices," said Robert Pavlik, chief market strategist at Banyan Partners LLC in Palm Beach Gardens, Florida, about the EU summit.
S&P 500 futures rose 0.5 points and were slightly above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures fell 1 point, and Nasdaq 100 futures were mostly flat.
Some of Wall Street's top analysts have published their research on Facebook Inc and most are cautiously optimistic. Facebook shares fell 2.6 percent to $32.25 in premarket trading after gaining more than 20 percent in the past two weeks.
Shares of Lennar Corp rose 3.5 percent to $28.36 premarket after the U.S. homebuilder reported a rise in new orders for the fifth straight quarter and said a slow and steady recovery was underway in the housing market.
A U.S. judge on Tuesday backed Apple's request to stop Samsung selling its Galaxy Tab 10.1 tablet in the United States, giving the iPhone maker a significant win in the global smartphone and tablet patent wars. Apple shares edged up in premarket trading.
Google will soon unveil a tablet co-branded with Taiwan's Asustek Computer and priced to compete with Amazon's Kindle Fire device, an Asustek executive said.
Shares of O-Reilly Automotive tumbled 17.6 percent to $79.44 premarket a day after the auto parts retailer revised its outlook.