TORONTO -- Canada's main stock index fell Wednesday on declines in three of its most influential sectors and ongoing concerns about the trade dispute between the U.S. and China.

The S&P/TSX composite index closed down 99.12 points at 16,327.35 with the energy, metals and mining, and financial sectors among the weakest.

Energy was the biggest loser on the day, falling 2.67 per cent. Crude oil prices dropped on a U.S. Energy Department weekly report pointing to surging U.S. stockpiles that have rekindled fears of a global supply glut.

The July crude contract was down $1.71 at US$61.42 per barrel and the August natural gas contract fell 8.2 cents to $2.57 per mmBTU.

Materials were two per cent lower as copper prices continued to fall.

The June gold contract was up $1.00 at $1,274.20 an ounce but the July copper contract was down 3.7 cents at $2.68 a pound.

First Quantum Minerals Ltd. decreased another 10.6 per cent on the day.

The influential financials sector was also down as CIBC shares lost 4.4 per cent after it kicked off quarterly bank results by missing expectations.

The gainers on the day were technology, consumer staples and health-care sectors.

Concerns about the trade dispute between the U.S. and China spurred on by tough rhetoric from both sides sent North American stock markets lower.

"Investors are continuing to digest a flurry of headlines...where both the U.S. and China have ratcheted up their rhetoric and even assumed a tougher approach," said Candice Bangsund, portfolio manager for Fiera Capital.

U.S. President Donald Trump on Wednesday threatened to blacklist as many as five more Chinese tech firms after last week's ban on Huawei Technologies. That came a day after U.S. markets gained after the Trump administration temporarily eased trade restrictions on the Chinese company.

China has also adopted a tough stance on negotiations even though it has more to lose than the U.S., said Bangsund.

"The U.S. is likely going to come out on top but at the same time 1/8China is 3/8 really reinforcing that these negotiations are hitting a fairly harsh stance and I think we're going to have a lot more volatility, a lot more uncertainty in the near-term until they can come to some sort of deal."

In New York, the Dow Jones industrial average was 100.72 points lower at 25,776.61. The S&P 500 index was down 8.09 points at 2,856.27, while the Nasdaq composite fell 34.88 points to 7,750.84.

The U.S. administration couldn't formally confirm that Trump will meet with his Chinese counterpart at an upcoming summit.

"We're in a bit of a deadlock. So I think with that is going to come a lot of volatility and uncertainty and just nervous markets in general," she added.

The Canadian dollar traded at an average of 74.57 cents US, compared with an average of 74.55 cents US on Tuesday.