* Oil jumps after air strikes on Yemen
* SanDisk tumbles in premarket after outlook cut
* Weekly jobless claims, flash Markit services sector PMI on tap
* Futures off: Dow 124 pts, S&P 14 pts, Nasdaq 46.25 pts
By Chuck Mikolajczak
NEW YORK, March 26 (Reuters) - U.S. stock index futures were lower on Thursday to put the S&P 500 on track for a fourth straight decline, after Saudi Arabia and its allies launched air strikes on Yemen.
* Oil prices spiked, with Brent crude up 3.4 percent to $58.40 and U.S. crude up 3.5 percent to $50.93 after warplanes from Saudi Arabia and its allies struck Shi'ite Muslim rebels fighting to oust Yemen's president. Halliburton shares gained 1.3 percent to $44.02 in premarket trade.
* U.S. stocks dropped on Wednesday as a slump in technology and biotechs sent the Nasdaq to its biggest decline in nearly a year while the S&P 500 fell through key support levels.
* Semiconductor stocks are likely to be under pressure for a fourth straight session, after SanDisk cut its first-quarter and 2015 revenue outlook and withdrew its other forecasts for the same time frame. Shares of SanDisk tumbled 13 percent to $70.60 before the opening bell. The PHLX semiconductor index had its biggest drop since Oct. 10 on Wednesday and is down 6.3 percent for the week.
* Weekly initial jobless claims data will be eyed at 8:30 a.m. (1230 GMT) for signs of continued strength in the labor market. Expectations call for claims to dip slightly to 290,000 from the 291,000 in the prior week.
* At 9:45 a.m. (1345 GMT), the preliminary or "flash" March reading of financial data firm Markit's Purchasing Managers Index on the services sector is scheduled for release.
* Lululemon Athletica lost 1.6 percent to $60.01 in premarket after the Canadian yogawear retailer forecast a weaker-than expected first quarter profit, months after it said margins would trough in 2015 as it continues to invest in improving quality and solving supply-chain problems.
* Consulting and outsourcing company Accenture Plc's quarterly net revenue rose 5 percent, helped by growth in its outsourcing business as North American companies look to cut costs. Its shares rose 2.6 percent to $90.49 before the opening bell.
* European shares fell with the London Stock Exchange leading the market lower on news Borse Dubai will sell its full stake in the company and ARM Holdings extending the previous session's steep losses.
* In Asia, Japan's Nikkei suffered its worst drop in 10 weeks on weakness in semiconductor stocks while Chinese stocks ended higher in a volatile volatile sessions as a sharp drop in Internet stocks was offset by a surge in energy shares.
* S&P 500 e-minis were down 14 points, or 0.68 percent, with 208,435 contracts changing hands.
* Nasdaq 100 e-minis were down 46.25 points, or 1.07 percent, in volume of 39,480 contracts.
* Dow e-minis were down 124 points, or 0.7 percent, with 35,886 contracts changing hands. (Reporting by Chuck Mikolajczak; Editing by Chizu Nomiyama)