The latest move comes after the completion of a review of Nifty Copper Operations announced this month as the mine continued to perform below expectations.
Metals X will process current ore stocks at the mine throughout next week.
According to the company, the mine and its associated processing facilities and infrastructure will be placed on care and maintenance.
Despite the improved resources and reserves following the Nifty reset plan announced in May, production has recently reduced and the review showed Metals X was unlikely to achieve planned production at a reasonable cost.
Metals X managing director Damien Marantelli said: “Alongside preserving and growing value for our shareholders, the company’s priority is the welfare of our 320 staff and approximately 110 contractors who have worked tirelessly to improve the culture and operational performance at Nifty.
“The company is in discussions with people affected by these changes. We will require a small workforce to ensure the mine and associated infrastructure is appropriately maintained so that it could be quickly returned to production, but there will be approximately 290 staff losses, the cost of which has been fully incorporated into the initial cost of implementing the suspension of operations.”
Metals X acquired Nifty as part of the takeover of Aditya Birla Minerals in August 2016.