Stock index futures pointed to a lower open on Wall Street on Wednesday, with futures for the S&P 500 down 0.5 percent, Dow Jones futures down 0.4 percent and Nasdaq 100 futures down 0.5 percent at 1000 GMT (5 a.m. ET).

European stocks were down 0.7 percent in morning trade, as this week's sharp retreat by commodities prompted investors to take a breather after an almost 2 percent rise in stocks in the first two sessions of the year.

Investors were braced for Portugal's T-bill auction, at which the country was expected to pay almost twice as much as it did in September, keeping it at the forefront of market concerns over the euro zone debt crisis.

Economic data on tap on Wednesday includes the ADP employment report and the ISM non-manufacturing index, both for December. Economists in a Reuters survey expected 100,000 jobs were created versus 93,000 jobs created in November.

Companies expected to report quarterly results include Family Dollar .

The dollar held firm on Wednesday, bolstered by further evidence the U.S. economic recovery was becoming self-sustaining, though gains against the euro were slowed by central bank demand for the single currency.

Time Warner , and U.S. private equity funds, KKR and TPG , were on a shortlist of potential buyers of assets belonging to Dogan Yayin , Turkey's biggest media group, sources familiar with the deal said.

A federal court in Alabama will centralize at least 1,200 civil lawsuits against Pfizer
over its smoking-cessation drug Chantix, which plaintiffs say can lead to suicide.

Mosaic Co shares rose 3 percent to $77.27 after the bell as it posted results.

Investors abandoned commodity shares on Tuesday, while fears of lower supermarket profits hit food retailers, sending the S&P and Nasdaq lower.

The Dow Jones industrial average <.DJI> added 20.43 points, or 0.2 percent, to 11,691.18. The Standard & Poor's 500 Index <.SPX> dipped 1.67 points, or 0.1 percent, to 1,270.20. The Nasdaq Composite Index <.IXIC> was off 10.27 points, or 0.4 percent, to 2,681.25.

(Reporting by Blaise Robinson; Editing by Dan Lalor)