* Final read on first-quarter GDP on tap, contraction expected
* Investors watching Iraq tension, crude oil rises early
* Bristol immunotherapy prolongs survival in melanoma trial
* Futures up: Dow 9 pts, S&P 500 2 pts, Nasdaq 0.5 pt
By Ryan Vlastelica
NEW YORK, June 25 (Reuters) - U.S. stock index futures were flat on Wednesday, following a sharp decline in the previous session, as investors looked ahead to a read on GDP expected to show the economy shrank in the first quarter.
* The final read on first-quarter gross domestic product is due at 8:30 a.m. (1230 GMT) and is seen showing a contraction of 1.7 percent, wider than the previous read of minus 1 percent.
* A negative read, which largely reflects the impact of harsh winter weather throughout the early months of the year, is likely priced into markets, but other economic indicators could drive trading. Durable goods orders, also due at 8:30 a.m., are seen as flat in May, while a June read on service sector business activity from financial data firm Markit is seen as essentially unchanged from May.
* The S&P 500 hit an intraday record in early trading on Tuesday, boosted by some positive economic data, but enthusiasm waned in the final hours of trading as concerns over Iraq returned to the forefront. The Dow posted its biggest daily decline in over a month.
* S&P 500 e-mini futures rose 2 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average e-mini futures rose 9 points and Nasdaq 100 e-mini futures rose 0.5 point.
* Geopolitical tensions will remain in view. In a mounting Sunni insurgency, militants in Iraq attacked one of the country's largest air bases. Separately, the first U.S. teams arrived to assess Iraqi security forces and decide how to help counter the violence.
* Investors are concerned about the impact prolonged turmoil in Iraq could have on oil prices, which are already up 3.8 percent this month. U.S. crude futures rose 0.6 percent to $106.64 per barrel in early trading. Many analysts have speculated that prices above $115 per barrel for an extended period will weigh on economic activity.
* The CBOE Volatility index spiked more than 10 percent on Tuesday, coinciding with the market's pivot lower, the biggest one-day pop for the "fear index" since April. Still, at 12.13 the VIX remains at very low levels from an historical basis.
* Bristol-Myers Squibb Co late Tuesday said a late-stage trial testing its immunotherapy nivolumab in advanced melanoma patients was halted early after it was determined that the drug was likely to prolong survival.
* The U.S. Air Force late Tuesday said it had awarded Lockheed Martin Corp a fixed-price contract valued at $1.9 billion to complete work on two missile-warning satellites as part of the Space-Based Infrared System.
* Golar LNG Ltd was one of the Nasdaq's most active premarket movers, falling 3 percent to $53.65 a day after it priced an offering of 11 million shares at a discount to its Tuesday close. (Editing by Chizu Nomiyama)