* North Korean attack rattles global markets
* GDP data, minutes from Fed meeting awaited
* Hewlett-Packard rises premarket after bullish outlook
* Futures down: Dow 45 pts, S&P 11.6 pts, Nasdaq 11.25 pts
By Ryan Vlastelica
NEW YORK, Nov 23 (Reuters) - U.S. stock index futures fell on Tuesday as rising tensions on the Korean peninsula added to concerns about global economic conditions.
* North Korea fired dozens of artillery shells on Tuesday, killing two soldiers and setting houses ablaze. South Korea returned fire.
* Global stock markets fell while the dollar edged higher as the geopolitical tension as well as worries over Ireland's debt crisis drove investors to the relative safety of the U.S. currency.
* Irish Prime Minister Brian Cowen challenging the opposition to approve an austerity budget and trigger an EU/IMF bailout before early elections, but Irish media reported Cowen may face calls to resign immediately or turn over leadership of his Fianna Fail party at a meeting later Tuesday.
* European stocks fell to a 3-week low, with banking stocks leading the way lower. U.S.-listed shares of Bank of Ireland sank 25 percent to $1.67, while HSBC Holding fell 1.7 percent to $51.38.
* S&P 500 futures fell 11.6 points and were below 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 futures dropped 45 points, and Nasdaq 100 futures lost 11.25 points.
* On the macroeconomic front, investors will keep an eye on the second estimate of third-quarter U.S. gross domestic product, which is expected to be revised upward. October home sales are also on tap and are expected to decline modestly after strong gains in the previous month.
* Economists expect GDP to come in at 2.4 percent, compared with 2 percent in the previous reading, while existing home sales are seen falling 1 percent after rising 10 percent last month.
* Minutes of the Federal Reserve's Nov. 3 Open Market Committee meeting, when it opted for more quantitative easing, will be released at 2 p.m. EST (1900 GMT).
* Dow component Hewlett-Packard Co rose 2.1 percent to $44.15 in premarket trading a day after the computer maker raised its 2011 outlook and posted stronger-than-expected quarterly profits.
* Hormel Foods Corp, Campbell Soup Co and Medtronic Inc are scheduled to report results on Tuesday.
* Bank shares weighed on Wall Street on Monday as Europe's debt crisis and fears of an insider trading probe sapped buying interest for most of the session.