(REUTERS) -- Stock index futures pointed to a lower open on Wall Street on Wednesday, with futures for the S&P 500, Dow Jones futures and Nasdaq 100 futures down 0.7 to 0.8 percent at 0918 GMT (05.18 a.m. EDT).

Macro economic data will be in the spotlight and investors will watch the Automatic Data Processing (ADP) at 1215 GMT, which will give further clues on the state of the employment market, while U.S. ISM non-manufacturing will be released at 1400 GMT.

Moody's has downgraded the ratings of conglomerate General Electric Co. and its finance unit General Electric Capital each by a notch, saying there were material risks associated with its funding model.

Justice Holdings , the London-listed investment firm, will pay about $1.4 billion in cash to buy a 29 percent stake in Burger King from its owner, private equity group 3G Capital Management LLC, in a move which will see the hamburger chain go public.

A Brazilian federal prosecutor has launched his second 20 billion real ($10.9 billion) lawsuit against U.S. oil company Chevron and driller Transocean, in relation to an oil leak discovered on March 4 in a field northeast of Rio de Janeiro.

A federal judge has rejected Bank of New York Mellon Corp.'s bid to dismiss a lawsuit by bondholders who invested in 26 trusts alleged to have contained risky mortgage loans from the former Countrywide Financial Corp.

The world's largest online coupon website Groupon Inc. is being sued by a shareholder for misleading investors about its financial results and concealing weak internal controls.

U.S. stocks fell on Tuesday, with the S&P 500 retreating from four-year highs after the U.S. Federal Reserve reduced expectations of another round of monetary stimulus.

The Dow Jones industrial average declined 0.5 percent, the Standard & Poor's 500 Index slipped 0.40 percent and the Nasdaq Composite Index dropped 0.20 percent.

(Reporting by Joanne Frearson; Editing by Hugh Lawson)