TORONTO -- Concerns about next week's U.S. election hung over traders' heads Thursday, pushing North American markets into the red.

"There seem to be a lot of concerns around the upcoming election in just a few days," said Steve Belisle, a senior portfolio manager of equities at Manulife Asset Management.

Hillary Clinton is still maintaining the lead but the gap between her and Donald Trump has narrowed.

"The polls keep shifting and now you have Clinton losing ground and Trump regaining some strength," said Belisle. "The race is now pretty close so it's pretty uncertain and the market doesn't like that."

In New York, the Dow Jones industrial average lost 28.97 points to 17,930.67, while the S&P 500 gave back 9.28 points to 2,088.66. The Nasdaq composite shed 47.16 points to 5,058.41.

North of the border, Toronto's S&P/TSX composite index slipped 11.30 points to close at 14,583.42, even as gold stocks -- used as a safe haven in times of uncertainty -- gained 1.6 per cent.

Gold stocks are "pretty much the only sector that's been gaining much in the past few days," Belisle said.

The health-care sector of the TSX slumped 3.98 per cent, while utilities stocks were down 0.93 per cent and energy stocks lost 0.66 per cent.

The Canadian dollar was at 74.72 cents US, up 0.07 of a U.S. cent from Wednesday's close.

The increased likelihood that the U.S. Federal Reserve will hike its trend-setting interest rates in December is also weighing on markets, said Belisle.

The central bank opted to keep rates unchanged after their two-day-long meeting, but they left the door open to an increase next month.

U.S. economic data has been strong recently, adding to the probability of a rate hike, said Belisle.

"The rate hike is now becoming well accepted by the market," he said. "I think it's a very likely scenario."

Belisle noted investors are also eagerly awaiting Friday's U.S. jobs figures, which will help confirm the likelihood that the Fed will proceed with the increase.

In commodities, the December crude oil contract fell 68 cents to US$44.66 per barrel and December natural gas was down two cents at US$2.77 per mmBTU.

The December gold contract fell $4.90 to US$1,303.30 an ounce and December copper contracts were up two cents at US$2.25 a pound.

In economic news, the U.S. Labor Department reported that claims for unemployment aid climbed by 7,000 to a three-month high of 265,000.

However, claims still remain at a low level, suggesting that most American workers enjoy job security.

Also on Thursday, the U.S. Labour Department reported that productivity increased at a 3.1 per cent rate in the third quarter -- the fastest pace in two years.

With files from the Associated Press