The company reported a headline loss for the three-months period of C$8.3 million, or 4c a share, which were below average analyst forecasts that called for nil per share, on expected revenue of $72.1 million.
Revenue fell 21.3% year-over-year to $60.72 million.
Copper Mountain said revenue in the period was impacted by a shipping delay at the Port of Vancouver over the quarter-end, which resulted in 1.1 million pounds of copper, 440 ounces of gold, and 4,000oz of silver not being recorded in the quarter. This revenue will be recognised in the fourth quarter.
Production at the Copper Mountain mine, near Princeton, was 10% lower at 22 million pounds of copper equivalent in the third quarter, which included 18.3 million pounds of copper, 7,500oz gold and 64,900oz of silver. It was however in line with expectations, the company said.
The company recorded higher operating costs because of increased cost of sales at $70.3 million. The increase was mainly owing to a $5.3 million inventory adjustment to the low-grade stockpile at net realisable value due to a nearly 5% decline in the average realised copper price of US$2.77/lb. Operating costs also reflected increases mainly associated with timing of planned major mine maintenance, fuel unit costs, and other consumable unit costs, the company said.
Total cash costs jumped 39% over the year-earlier period to US$2.25/lb sold, net of precious metal by-product credits.
Copper Mountain said it was on track to achieve its full-year 2018 production guidance of 80 million pounds of copper and expects a strong fourth quarter operational performance.
The stock fell 4% Wednesday to a new 12-month low of C94c, which gave the company a market value of $178.76. million.