Wall Street was lower on Wednesday as Brent crude slid back towards the 11-year low it hit last week and Apple weighed on all three major indexes.
Crude oil gave up its gains from Tuesday after forecasts of a short winter in North America and Europe piled pressure on the oversupplied commodity.
The S&P 500 energy sector was the most declined among the 10 major sectors, with a 1.03 percent fall. Shares of Exxon were down 0.8 percent at $78.56, while Chevron was down 1.2 percent at $90.11.
The energy sector has fallen 23.49 percent for the year, easily the worst performer on the index, followed by a 9.16 percent decline in materials, caused primarily by a rout in commodities.
"Traders are ready to tie a bow on 2015 very happily, because it was one of those years when most asset classes didn't work," said Jeff Kravetz, regional investment director at U.S. Bank Wealth Management in Phoenix, Arizona.
At 12:33 p.m. ET (1533 GMT), the Dow Jones industrial average was down 51.98 points, or 0.29 percent, at 17,669, the S&P 500 was down 7.34 points, or 0.35 percent, at 2,071.02 and the Nasdaq Composite index was down 18.99 points, or 0.37 percent, at 5,088.95.
"The next few days, you're not going to get a lot of action here," Kravetz said, adding that most traders have likely already closed off their positions for the year.
Trading volumes are expected to remain thin on the last trading days of the year.
Apple was the biggest drag on all three indexes, falling 1 percent to $107.60. Concerns about potentially soft iPhone sales have hit the stock in recent weeks.
The S&P 500 stayed positive for the year, holding on to a meager 0.6 percent gain, while Nasdaq was up 7.44 percent. The Dow, however, was down 0.87 percent in 2015.
Pep Boys was down 3 percent at $18.38. Carl Icahn agreed to buy the auto parts maker for about $1.03 billion, after Japan's Bridgestone said it would not counter his offer. Icahn Enterprises was down 1.5 percent at $60.60.
Fairchild Semiconductor was up 3.3 percent at $20.68 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.
Weight Watchers soared 21.3 percent to $23.45, extending gains for the third day. The company launched an advertising campaign last week featuring Oprah Winfrey.
Declining issues outnumbered advancing ones on the NYSE by 1,954 to 1,011. On the Nasdaq, 1,721 issues fell and 1,022 rose.
The S&P 500 index showed 15 new 52-week highs and no new lows, while the Nasdaq recorded 42 new highs and 41 new lows. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Don Sebastian)