Canada's main stock index ended lower on Wednesday, hurt by losses among miners with weaker copper and gold prices, a pullback in technology stocks led by Shopify Inc (SHOP.TO) and a fall in shares of Canadian National Railway Co (CNR.TO).

Better-than-expected quarterly earnings boosted Royal Bank of Canada (RY.TO), the country's largest bank by market value, while several other heavyweight financial stocks also gained.

The Toronto Stock Exchange's S&P/TSX composite index ended down 61.92 points, or 0.39 per cent, at 15,967.72. Seven of the index's 10 main sectors finished lower, with three decliners for every two advancers overall.

CN Rail fell as much as 4.9 per cent, to its lowest level since March, before recovering somewhat to end down 1.8 per cent at $98.20. That was its worst one-day fall since July 26.

CN Rail's chief financial officer said its fourth quarter may be a "bit more difficult" because of an early winter and a couple of derailments.

Royal Bank of Canada gained 0.9 per cent to $101.38, while the overall financial sector rose 0.4 per cent.

Shopify Inc fell 7 per cent to $133.40, erasing gains the e-commerce software company's stock had made after the Black Friday and Cyber Monday shopping days. The technology group fell 2.6 per cent overall.

The materials group, which includes precious and base metals miners and fertilizer companies, lost 1.3 per cent as prices for gold as well as copper, aluminum and other base metals fell.

Potash Corp (POT.TO) added 0.6 per cent to $25.08 after its chief executive said he expects a "very tight" balance of potash supply and demand in 2018 and that the company had received "broad interest" from Chinese buyers interested in its stake in a Chilean lithium producer.