Crude oil fell below $68 per barrel a day after OPEC decided not to cut output, which could leave markets over supplied. The 7 percent decline was the biggest one-day drop since May 2011, with prices lowest since 2010.

"Crude seems to have no floor right now, and we could easily see the price drop into the low $60s," said Tony Roth, chief investment officer at Wilmington Trust in Wilmington, Delaware.

The Energy Select Sector SPDR exchange-traded fund (>> Energy Select Sector SPDR (ETF)) fell 6.4 percent to $79.82 while the S&P energy index <.SPNY> lost 6.3 percent, extending its run as the worst-performing S&P industry group of the year. Exxon Mobil Corp (>> Exxon Mobil Corporation) lost 4.2 percent to $90.54 while Chevron Corp (>> Chevron Corporation) fell 5.4 percent to $108.87; both are Dow components.

Shale energy companies saw outsized declines, as $70 oil is considered the level at which shale becomes an unprofitable alternative. Denbury Resources (>> Denbury Resources Inc.), QEP Resources (>> QEP Resources Inc) and Newfield Exploration (>> Newfield Exploration Co.) all lost more than 15 percent.

Oil weakness boosted airlines, which are inversely correlated to oil prices. Southwest Airlines (>> Southwest Airlines Co) rose 6.5 percent to $41.82 as the S&P 500's biggest percentage gainer, followed by Delta Air Lines (>> Delta Air Lines, Inc.), up 5.5 percent to $46.67.

Retailers rallied as lower gas prices could increase consumer spending. Wal-Mart Stores Inc (>> Wal-Mart Stores, Inc.) rose 3 percent to $87.54, boosting the Dow, while the S&P 500 Retailing index <.SPXRT> was up 1.4 percent.

"[Oil] this low should be very additive to economic activity, not just with gas prices but across the economy," said Roth, who oversees $80 billion in assets. "Early holiday shopping numbers should come in pretty strong."

The Dow Jones industrial average <.DJI> rose 0.49 points to 17,828.24, the S&P 500 <.SPX> lost 5.27 points, or 0.25 percent, to 2,067.56 and the Nasdaq Composite <.IXIC> added 4.31 points, or 0.09 percent, to 4,791.63.

Major indexes rose for a sixth straight week, the S&P's longest streak since November 2013. For the week, the Dow rose 0.1 percent, the S&P rose 0.2 percent and the Nasdaq rose 1.7 percent.

For November, the Dow rose 2.5 percent, the S&P added 2.5 percent and the Nasdaq 3.5 percent.

NYSE decliners issues outnumbered advancers 1,846 to 1,137, for a 1.62-to-1 ratio; on the Nasdaq, 1,777 issues fell and 875 advanced, for a 2.03-to-1 ratio.

The S&P 500 posted 152 new 52-week highs and 21 new lows; the Nasdaq Composite recorded 163 new highs and 80 new lows.

About 4.2 billion shares traded on all U.S. platforms, according to BATS exchange data.

(Editing by Nick Zieminski)

By Ryan Vlastelica