Chemicals and explosives maker Orica expects to cut 700 jobs before the end of the year as a downturn in commodity prices forces its miner customers to cut costs.

Chief executive Ian Smith said the company has so far given the bad news to more than half of the affected workers. As the world’s largest supplier of explosives and blasting systems to the mining, quarrying and infrastructure sectors, Orica is being adversely affected by plunging commodity prices. The news…