Mexico-focused miner Endeavour Silver warned on Thursday that it would fall short of its 2018 production guidance and that its costs would also be affected, citing delayed commercial production at its El Compas mine, lower grades at Bolañitos and lower mine output at Guanaceví.

In the third quarter, TSX- and NYSE-listed Endeavour produced 1.43-million ounces of silver and 12 968 oz of gold, resulting in silver equivalent production of 2.4-million ounces.

Compared with the third quarter of 2017, silver production was up 13% and gold production fell by 5%. Silver-equivalent output improved by 5%.

The silver-equivalent production increased on the back of significantly improved silver and gold grades at El Cubo being mined from the centre of the Villalpando-Asuncion orebody. The higher silver and gold production at El Cubo were offset by lower silver and gold grades at Guanaceví mined near the bottom of the Porvenir Norte and Santa Cruz orebodies and lower gold grades at Bolañitos in the upper Plateros orebody.

Endeavour Silver said that Guanaceví’s throughput and grades were expected to continue to rise as the newly developed, higher grade Milache orebody entered production this month. Grades at the Bolañitos gold mine were also expected to improve in the fourth quarter.

At El Compas, the plant is scheduled to resume operations this week, after the temporary halt in August to allow the fine tailings area to be dewatered, expanded and under-drains improved. Commerical production is expected in the fourth quarter.

For the nine months ended September, silver production was 4.14-million ounces and gold production was 39 850 oz, resulting in silver-equivalent production of 7.1-million ounces.

Based on the performance to date, the midtier miner estimates a 5% production shortfall on the 2018 consolidated production guidance.