TORONTO -- Lower commodity prices weighed on the Toronto stock market Wednesday, pulling the index down more than 100 points at the close.

The Toronto Stock Exchange's S&P/TSX composite index fell by nearly one per cent, or 138.53 points to 14,626.24.

Gold stocks were the largest decliner on the exchange, with the sector pulling back 7.26 per cent, with December gold fading $16.40 to US$1,329.70 an ounce.

Materials stocks, which including mining and fertilizer companies, followed in losses, with the sector contracting 5.76 per cent on the TSX.

Oil prices were also volatile following a report that showed higher than expected U.S. inventories of crude and gasoline.

The U.S. Energy Information Administration reported that domestic crude supplies rose by 2.5-million barrels last week, significantly higher than what was expected.

"That just means we have too much supply right now and not enough demand," said Craig Jerusalim, a Canadian equities portfolio manager at CIBC Asset Management.

He noted that even if the members of OPEC agree on a production cap at its next meeting in September, it will still likely not be enough to inflate oil prices to more sustainable operational levels for crude companies.

"Unfortunately they'll be capping production at levels that are historic highs," said Jerusalim. "They probably won't take the painful steps necessary to actually cut production."

Oil prices have been hovering around the US$50 mark for some time -- a far cry from the US$100 a barrel prices seen in 2014.

The October crude contract was down US$1.33 at US$46.77 per barrel.

The Canadian dollar, which often traces the path of oil, fell 0.12 of a cent to 77.34 cents US.

Meanwhile, some of the losses on the TSX were partially offset by another strong earnings report from one of Canada's largest banks.

Royal Bank (TSX:RY) reported a 17 per cent jump in profit to $2.895 billion and total revenue of $10.26 billion during the quarter ending July 31.

Its shares dipped 37 cents, or 0.45 per cent, to $81.86.

Meanwhile, in other commodities, September copper lost four cents to US$2.08 a pound, while October natural gas contracts were up four cents at US$2.84 per mmBTU.

In New York, the Dow Jones industrial average was down 65.82 points at 18,481.48, the broader S&P 500 composite index declined 11.46 points to 2,175.44 and the Nasdaq composite lost 42.38 points to 5,217.70.

Traders continue to wait for an important speech Friday by U.S. Federal Reserve chairwoman Janet Yellen following a summer symposium in Jackson Hole, Wyo. What will be particularly watched is whether she sheds any light on the central bank's thinking on interest rate hikes.

"Whether we get an interest rate hike in September (or) December or the next one is 2017, it's likely that interest rates are not going to be much higher than where they are today," said Jerusalim.