Canadian gold major Goldcorp has reported a third-quarter net loss of $101-million, compared with $111-million a year earlier, and a 20% drop in production during a transition period at its flagship Peñasquito mine, in Mexico.

The Vancouver-based miner produced 503 000 oz at an all-in sustaining cost (AISC) of $999/oz, compared with 633 00 oz at an AISC of $827/oz in the September 2017 quarter.

Goldcorp explained that production was affected by the lower output of all metals at Peñasquito, as a result of lower throughput and planned lower grades from stockpiles during the commissioning of the now fully constructed Peñasquito pyrite leach project (PLP).

Commissioning of the PLP had started, with first gold and commercial production forecast for the December quarter.

Production would “substantially” increase in the fourth quarter to about 620 000 oz at an AISC of $750/oz, as most of Peñasquito’s production would come from higher grade ore from the main Penasco pit.

“The commissioning of the PLP at Peñasquito, ongoing development of the materials handling system at Musselwhite and the near completion of the ramp-up at both Cerro Negro and Éléonore are expected to lead to significantly improved gold production and costs in the fourth quarter of 2018,” CEO David Garofalo said.

Further, he reported that the group’s focus on exploration had assisted in replacing gold reserve depletion across its operating assets, establishing a foundation to achieve its reserve target of 60-million ounces by 2021.

Since the start of the group’s 20/20/20 plan last year, Goldcorp has increased its reserve ounces by 2.8-million ounces.

At June 30, the group’s proven and probable gold mineral reserves totalled 52.8-million ounces, compared with 53.5-million ounces at June 30, 2017.

Measured and indicated gold mineral resources decreased from 37.1-million ounces to 35.2-million ounces, primarily owing to the impact of the successful conversion of indicated mineral resources into proven and probable mineral reserves at Musselwhite, Cerro Negro, Peñasquito and Porcupine. 

Inferred gold mineral resources decreased to 17.5-million ounces from 20.0-million ounces.