Zimplats has decided to stop all mining activities at the Bimha Mine in Zimbabwe, following an underground collapse at the facility in July this year.
The move will cost the company about 70,000 platinum ounces, around 30% of the entire $100m production.
The closure will not affect production from the other three mines and the ramp-up of Mupfuti mine will continue as planned.
Zimplats said that a collapse in a section of the underground working area was triggered by accelerated deterioration of ground conditions associated with a major fault, the Mutambara Shear, which cuts through the mining area.
The company has indicated that ground conditions have continued to deteriorate, which has lead to the closure of the mine.
Bimha mine accounted for 41% of Zimplats' entire 4.96 million tonnes of ore production in 2013, with the remaining coming from the three other mines operated by the company.
The closure will prevent Zimplats from reaching its second phase design capacity of 6.2 million tonnes a year in the coming years.
The company, which has produced 240,000 platinum ounces this year, has appointed a team of in-house and independent advisers to carry out detailed investigations to re-engineer and/or halt the mine stability concerns.
Two fleets from the Bimha mine have been deployed to the other mines in order to mitigate production losses.