US STOCKS-Futures flat; oil rout looks to weigh on energy
* Oil falls 6.5 percent, Exxon tumbles in pre-market
* Dow on track to turn negative for the week
* Dow and S&P each down 3 points, Nasdaq up 8.75 points (Updates prices)
By Ryan Vlastelica
NEW YORK, Nov 28 (Reuters) - U.S. stock index futures were mostly flat on Friday, as the market's recent upward bias looked to continue in a holiday-shortened session, though energy shares saw heavy pressure as crude oil tumbled to a four-year low.
Wall Street was closed for the U.S. Thanksgiving holiday on Thursday and will shut three hours earlier on Friday. Trading volatility could spike since many market participants were extending the holiday.
U.S. crude futures slumped 6.3 percent to $69.06 per barrel. It was the biggest one-day drop for crude since August 2011, and the decline brought prices to their lowest since 2010. On Thursday, OPEC decided not to cut output, which could leave oil markets heavily oversupplied.
Energy shares have been under pressure throughout 2014 as crude prices have slid more than 30 percent from a recent closing high. The S&P energy sector is the only S&P 500 industry group to be lower for the year, down 4.3 percent.
The Energy Select Sector SPDR exchange-traded fund fell 4.3 percent to $81.60 in pre-market trading. Exxon Mobil Corp lost 3.5 percent to $91.20 while Chevron Corp fell 4 percent to $110.55; both stocks are Dow components. Halliburton Co lost 4.2 percent to $45.35. Continuación...