Stock index futures pointed to a mixed open on Wall Street on Tuesday following the previous session's sharp losses, with futures for the S&P 500 up 0.49 percent, Dow Jones futures up 0.21 percent and Nasdaq 100 futures down 0.17 percent at 0831 GMT.

European stocks were up 1 percent in morning trade in a tentative rebound after a 3.3 percent drop in the previous session, but brewing concerns over the region's debt crisis kept investors on edge.

The market awaited the preliminary (second) estimate of U.S. Q3 Gross Domestic Product. Economists in a Reuters survey forecast a 2.5 percent annualized rate of growth, a repeat of the advance (first) Q3 estimate.

Ratings agencies Standard & Poor's and Moody's said on Monday there will be no immediate downgrade of their credit ratings on the United States due to the failure of a congressional super committee to reach an agreement on debt reduction.

But Fitch, the third leading ratings agency, which currently has the most positive rating of the three on U.S. debt, said it could cut the outlook on its triple-A rating, with a downgrade an outside possibility.

Video rental company Netflix Inc said late on Monday that it raised $400 million in fresh capital by selling convertible debt to long-time backer Technology Crossover Ventures and stock to funds managed by T. Rowe Price.

KKR & Co and Japanese trading house Itochu Corp have joined forces in a roughly $7 billion bid for U.S. oil and gas group Samson Investment Co, in a rare link-up between a major private equity firm and a Japanese company.

U.S. regulators have informed Bank of America's board that the company could face public enforcement action if they are not satisfied with recent steps taken to strengthen the bank, the Wall Street Journal said, citing people familiar with the situation.

Lockheed Martin Corp has won a U.S. Air Force contract potentially worth $7.4 billion for upgrades to its problem-plagued F-22 Raptor fighter jet, designed to be the premier U.S. combat plane.

Samsung Electronics <005930.KS>, the world's top TV maker, is in last-stage talks with Google to roll out its Google TVs, the head of Samsung's TV division told reporters on Tuesday.

The dollar stuck near a six-week high against a basket of currencies on Tuesday on a sharp pullback in global risk appetite as the sovereign debt storm intensified on both sides of the Atlantic.

U.S. stocks fell for a fourth session on Monday, as the lack of progress in dealing with heavy debt both in the United States and Europe further sapped investor confidence in equities.

The Dow Jones industrial average <.DJI> slid 248.85 points, or 2.11 percent, to end at 11,547.31. The Standard & Poor's 500 Index <.SPX> lost 22.67 points, or 1.86 percent, to finish at 1,192.98. The Nasdaq Composite Index <.IXIC> dropped 49.36 points, or 1.92 percent, to close at 2,523.14.

(Reporting by Blaise Robinson; Editing by Erica Billingham)