U.S. stock index futures slipped on Wednesday, indicating the S&P 500 may snap a three-day winning streak after weaker-than-expected euro zone economic data and ahead of a report on the U.S. housing market.

European shares fell for a second straight session as recession concerns increased after data showed the euro zone's service sector unexpectedly shrank and amid residual worries about Greece despite its success in getting a bailout.

The FTSEurofirst 300 <.FTEU3> index of top European shares was down 0.7 percent and the euro edged down 0.1 percent.

But even with the weak European data, market sentiment remained positive in a market that has seen the benchmark S&P index rise 8.3 percent for the year on improving U.S. data and hopes the euro zone debt crisis could be held in check.

We still have a slowing economy in Europe. It's just a function of how long their shallow recession lasts, but we will take a shallow recession over what the alternative was going to be, if not for the Greek deal and the ECB's intervention, said Art Hogan, managing director of Lazard Capital Markets in New York.

Investors will look to the National Association of Realtors' January existing home sales at 10 a.m. EST (1500 GMT). Economists in a Reuters survey forecast 4.65 million annualized unit total versus 4.61 million in December.

From the beginning of the financial crisis, to a person, everybody you spoke to said this thing turns around when housing bottoms out. If we start to get that type of data, which we are starting to get, we are going to certainly see a market that can continue its upward trend here, said Hogan.

S&P 500 futures fell 1.5 points and were slightly below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures lost 1 point, and Nasdaq 100 futures shed 3 points.

Dell Inc slumped 7.2 percent to $16.90 in premarket trading after the world's No. 3 personal computer maker forecast

revenue below expectations late Tuesday.

Toll Brothers Inc dropped 5.1 percent to $22.50 after the luxury homebuilder swung to a quarterly loss as fewer deliveries and more contract cancellations hurt revenue.

Garmin Ltd jumped 9.6 percent to $49 after reporting a better-than-expected quarterly profit as revenue from its personal navigation devices rose and demand for its outdoor and fitness products jumped.

Fellow computer maker Hewlett-Packard Co is set to report earnings later Wednesday. The market expects a profit of 87 cents per share, down from $1.36 one year ago.

Other companies due to announce results later in the day include Express Scripts Inc , TJX Cos Inc and Analog Devices Inc .

According to Thomson Reuters data through Tuesday morning, of the 418 companies in the S&P 500 that have reported earnings, 64 percent have topped analysts' expectations.

Wells Fargo & Co is buying an energy lending business from BNP Paribas SA in the U.S. bank's latest acquisition from a European bank seeking to shrink its balance sheet.

Asian shares eked out modest gains on doubts about Greece and concerns grew about rising oil prices.

On Tuesday the Dow Jones industrial average <.DJI> finished up 15.82 points, or 0.12 percent, at 12,965.69 after briefly breaking 13,000 for the first time since May 2008. The Standard & Poor's 500 Index <.SPX> ended up 0.98 point, or 0.07 percent, at 1,362.21. The Nasdaq Composite Index <.IXIC> was down 3.21 points, or 0.11 percent, at 2,948.57.

(Reporting By Chuck Mikolajczak; editing by Jeffrey Benkoe)