* Exxon, Chevron slide as crude gives up gains
* Pep Boys down after Bridgestone pulls out of buyout
* S&P 500 marginally positive for year
* Futures down: Dow 50 pts, S&P 5.5 pts, Nasdaq 8.5 pts (Adds details, updates prices)
By Abhiram Nandakumar
Dec 30 (Reuters) - U.S. stock indexes were set to open marginally lower on Wednesday as crude oil gave up Tuesday's gains after forecasts suggested winter in Europe and the United States would be short-lived.
Global stocks followed crude prices lower, as demand remains sluggish and supply continues unabated.
Shares of Exxon and Chevron were down about 1.3 percent in premarket trading.
The S&P 500 energy sector is down 22.68 percent for the year, easily the worst performer on the index, followed by an 8.72 percent decline in materials, caused by the rout in commodities.
Trading volumes are expected to remain thin on the last trading days of the year.
"What I would expect for today and tomorrow ... would be tactical trading rather than investment strategies at work," said Jack Ablin, chief investment officer at BMO Private Bank in Chicago.
At 8:39 a.m. ET (1339 GMT), Dow e-minis were down 50 points, or 0.28 percent, with 13,365 contracts changing hands. S&P 500 e-minis were down 5.5 points, or 0.27 percent, with 69,751 contracts traded. Nasdaq 100 e-minis were down 8.5 points, or 0.18 percent, on 12,595 contracts.
U.S. stocks closed sharply higher on Tuesday on a rally in tech stocks led by Apple and Amazon.
The S&P 500 closed Tuesday in positive territory for the year, up less than a percent, while the Nasdaq Composite was up 7.85 percent. The Dow Jones industrial average, however, was down 0.57 percent in 2015.
Data is expected to show a half percent rise in an index of pending home sales in November, after inching up 0.2 percent in October. The data by the National Association of Realtors is due at 10:00 a.m. ET.
Pep Boys was down 2.9 percent at $18.40. Japan's Bridgestone said it would not counter Carl Icahn's raised offer for the auto parts maker.
Fairchild Semiconductor was up 2.9 percent at $20.60 after it received a revised offer from the Party G Group, with new terms on termination fees if the takeover fails to secure regulatory approvals. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Don Sebastian)