Futures edge up after sell off; GDP on tap

NEW YORK (Reuters) - U.S. stock index futures were inching higher on Friday after major indexes suffered their biggest drop since July, ahead of data on economic growth and consumer optimism.

* Major indexes saw their biggest declines since July 31 on Thursday in a broad sell off, with the S&P 500 falling through a key technical support level, as Apple slumped and the dollar hit a four-year high.

* The S&P has dropped for four of the past five sessions and closed below its 50-day moving average for the first time since Aug 15. That level had previously served as support, and a protracted period underneath it could signal further losses.

* Economic data due includes a final reading of gross domestic product growth in the second quarter at 8:30 a.m. EDT. Expectations call for expansion of 4.6 percent versus the prior reading of 4.2 percent.

* Later in the session at 9:55 a.m.EDT, investors will eye the Thomson Reuters/University of Michigan's final September reading on consumer sentiment. The current estimate stands at 84.7 versus a preliminary reading of 84.6.

* Nike shares were trading up 7.2 percent to $85.50 before the opening bell after the world's largest sportswear maker reported a better-than-expected quarterly profit.

* Micron Technology shares were climbing 6.2 percent to $33.65 in premarket after the memory chipmaker posted fiscal fourth-quarter results and a revenue outlook that impressed Wall Street.

* U.S.-listed shares of Blackberry were up 4 percent to $10.19 in premarket after the company reported a smaller quarterly loss in an early sign that its drawn-out turnaround efforts might be working.

* The sharp sell-off in the U.S. on Thursday hit European and Asian equities, as European shares slipped to a new one-month low while the Nikkei share average ended 0.9 percent lower. [.EU] [.T]

* S&P 500 e-minis were up 2 points, or 0.1 percent, with 153,219 contracts changing hands.

* Nasdaq 100 e-minis were gaining 4.75 points, or 0.12 percent, in volume of 28,784 contracts.

* Dow e-minis <1YMc1> were up 26 points, or 0.15 percent, with 20,956 contracts changing hands.

(Editing by Bernadette Baum)