Adding to the pressure, the U.S. dollar climbed to a fresh three-month high against the yen, benefiting from year-end flows and a view that the U.S. economy is stabilizing.
Equities and the greenback have moved in an inverse direction of late, though the relationship has shown some signs of deterioration.
Airline stocks could see interest after Japan Airlines Corp <9205.T> tumbled as much as 32 percent to a record low on concerns the carrier will be restructured in bankruptcy court. American Airlines and Delta Air Lines Inc have been courting JAL with rival offers of financial aid.
Shares of American Air parent AMR Corp fell 1.7 percent to $7.64 in light premarket trading.
Marvell Technology Group Ltd and Nvidia Corp rose after Kaufman Bros upgraded the stocks to buy, saying the chipmakers could benefit from improved demand for personal computers.
Marvell was up 0.9 percent to $20.45, and Nvidia gained 1.6 percent to $18.30.
Action is expected to be muted through the shortened week, with investors cooling their heels after a nearly 25 percent run-up for the S&P 500 this year.
There are some people that have made some money this year that have made some good bets, and at the end of the year they're going to take profits, said Tommy Williams, president of Williams Financial Advisors in Shreveport, Louisiana.
Trading is going to be so light as we're winding the year down.
S&P 500 futures fell 3.7 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 lost 47 points, and the Nasdaq 100 futures gave up 6 points.
Overseas, European shares were broadly lower in thin trading Wednesday, while Tokyo's Nikkei <.N225> dropped nearly 1 percent in its last trading session of the year. The Nikkei booked a 19 percent gain for 2009, and the pan-European FTSEurofirst 300 <.FTEU3> was on track for a 26 percent advance for the year.
On the data front, the Institute for Supply Management-Chicago's business barometer for the U.S. Midwest will be released at 9:45 a.m. EST (1445 GMT). Economists expect a December reading of 55 compared to 56.1 the month before, according to Reuters data.
Pfizer Inc said Tuesday it ended a late-stage lung cancer study for its experimental drug figitumumab. Pfizer slipped 1 percent to $18.40.
U.S. stocks broke a six-day winning streak on Tuesday, closing slightly lower on low volume.
(Editing by Jeffrey Benkoe)