Miner Teck Resources Ltd reported a quarterly profit slightly below analysts' estimates, hurt by lower copper and zinc prices. Shares of the company fell 0.5pc.

Oil and gas producer Cenovus Energy fell 2.3pc after the company missed quarterly profit estimates as the production cuts ordered by Alberta's provincial government in Canada hit output and higher Canadian crude prices hurt refining margins.

At 9:40 a.m. ET (1340 GMT), the Toronto Stock Exchange's S&P/TSX Composite index was down 48.11 points, or 0.29pc, at 16,563.73.

All of the index's 11 major sectors were lower, led by the energy sector's 1pc drop, hurt by Cenovus.

The materials sector, which includes precious metal miners, lost 0.8pc, hurt by an 8.8pc fall in shares of OceanaGold Corp after the miner reported quarterly results.

OceanaGold fell the most on the TSX, followed by shares of Celestica Inc, which dropped 6.8pc.

Among other reports, Husky Energy Inc posted a better-than-expected quarterly profit, as higher Canadian crude prices following the Alberta government's mandatory output cuts more than offset the company's lower production and weak refining margins.

The financials sector and the industrials sector each slipped 0.1pc.

On the TSX, 56 issues were higher, while 171 issues declined for a 3.05-to-1 ratio to the downside, with 13.85 million shares traded.

The largest percentage gainers on the TSX were shares of Mullen Group Ltd, which jumped 6.6pc followed by shares of Precision Drilling, which rose 4pc.

The most heavily traded shares by volume were Lundin Mining and OceanaGold.

The TSX posted six new 52-week highs and two new lows.

Across all Canadian issues, there were 25 new 52-week highs and nine new lows, with total volume of 23.51 million shares.