New York - Energy shares were once against the biggest losers of the day in morning trading on Thursday, continuing a recent trend of weakness amid falling oil prices.
The S&P energy index fell 1.5 percent and was the biggest decliner among the ten primary S&P 500 sectors.
It has fallen almost 14 percent from a record high in late June, putting the sector well within correction territory, defined as a 10 percent decline from a peak.
Including Thursday's move, the index has posted declines of more than 1 percent on ten occasions since the start of September.
Crude oil fell 0.9 percent to $86.55 (R956) per barrel, dropping to its lowest level since April 2013.
From a closing high in September 2013, oil is down more than 21 percent, putting the commodity into bear market territory.
Oil was pressured by a supply glut and concerns over global economic growth.
The Philadelphia SE Oil Service sector fell 2.6 percent.
Among specific companies, Halliburton fell 2.9 percent to $58.66 while Newfield Exploration lost 4.1 percent to $32.44.
Exxon Mobil lost 1.2 percent to $93.49 and Chevron was down 1.6 percent to $116.08.
Index snapshot at 10:12 EDT (17:12 SA time):
* S&P 500 fell 12.22 points, or 0.62 percent.
* Nasdaq Comp lost 32.93 points, or 0.74 percent.
* Dow industrials dropped 100.63 points, or 0.59 percent.
* Russell 2000 dropped 13.87 points, or 1.26 percent.
* S&P MidCap sank 13.68 points, or 1.01 percent.
* S&P SmallCap lost 6.94 points, or 1.1 percent. - Reuters