Futures for the Dow Jones industrial average, the S&P 500 and the Nasdaq 100 are down 0.2 to 0.5 percent, pointing to a lower start when the U.S. markets open on Wednesday and extending the previous session's sharp losses.

European shares were down 1 percent on Wednesday morning, losing ground for the third straight session, with banking and mining shares taking the most points off the index.

At 8:15 a.m. EDT, Automatic Data Processing releases its August employment report. Economists in a Reuters survey expect 250,000 jobs were lost in August versus 371,000 job losses in July.

The Labor Department releases revised Q2 productivity and unit labor costs at 8:30 a.m. EDT. Economists in a Reuters survey forecast a rise of 6.4 percent in productivity and a 5.8 percent fall in unit labor costs. These are repeats of the figures in the previous report.

The Commerce Department releases July factory orders at 10 a.m. EDT. Economists in a Reuters survey expect an increase of 2.2 percent compared with a 0.4 percent rise in June.

At 2p.m. EDT, the Federal Open Market Committee issues minutes from its meeting of August 11-12.

Brown-Forman Corp , the U.S. maker of Jack Daniel's whiskey and Southern Comfort, is reporting first-quarter results with analysts expecting earnings per share of 0.62 cents compared to 0.69 cents a year ago.

The Obama administration has granted as much as $1.6 million in aid to help trade groups promote ethanol, natural gas, propane and biodiesel products, whose clean-energy selling points happen to fit with the administration's push to cap carbon emissions, reported the New York Times.

U.S. stocks fell for a third straight day on Tuesday, spooked by uncertainty over the health of financials and concerns that the explosive rally since March may have run ahead of economic reality.

The Dow Jones industrial average <.DJI> tumbled 2 percent, the Standard & Poor's 500 Index <.SPX> fell 2.2 percent and the Nasdaq Composite Index <.IXIC> slid 2 percent.

(Reporting by Joanne Frearson; Editing by Hans Peters)