Wall St set to open lower on euro zone, ADP data

Euro zone factories sank further into decline last month, with the downturn hitting Italy and Spain hard and appearing to take root among core members France and Germany. Eu ropean shares erased earlier gains, with the FTSEurofirst 300 down 0.4 percent.

Investor caution ahead of Friday's key payrolls report was increased after a report by payrolls processor Automatic Data Processing showed U.S. private employers added 119,000 jobs in April, well short of expectations.

The data came a day after the Dow closed at its highest level in more than four years on strong manufacturing data.

"These aren't good numbers this morning, they are certainly on the low end of expectations. However, in the broader theme you can't look at these numbers alone, you can't isolate them from the broader picture, which is continuing expansion, continuing improvement in U.S. manufacturing," said Peter Kenny, managing director at Knight Capital in Jersey City, New Jersey.

"It's at the low end of the range and I know it's disappointing, but in the broader context it's not really a game changer."

The Commerce Department releases March factory orders at 10 a.m. EDT (1400 GMT). Economists look for a 1.6 percent drop, compared with a 1.3 percent rise in February.

S&P 500 futures fell 6.5 points and were 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 dipped 54 points, and Nasdaq 100 futures lost 14 points.

CVS Caremark Corp gained 2.9 percent to $46 in premarket trading after the drugstore operator and pharmacy benefits manager posted a sharp rise in first-quarter sales and raised its profit forecast.

Results are also expected from 31 S&P 500 companies on Wednesday, including Visa Inc , MasterCard Inc , Whole Foods Market Inc and Symantec Corp .

Of the 321 S&P 500 companies that have reported results so far, 71.3 percent have topped analysts' estimates, according to Thomson Reuters data through Tuesday morning.

Chesapeake Energy Corp dropped 11.5 percent to $17.34 premarket after the company reported that natural gas production barely changed in the first quarter from late 2011. Als o, Reuters reported Chief Executive Aubrey McClendon ran a $200 million hedge fund on the side.

American Eagle Outfitters Inc