Impala Platinum shares shot up more than 10% on Wednesday as the world's second-largest platinum producer's restructuring strategy gained momentum, with improved production at its Rustenburg mines and talks starting on the sale of one big shaft.

Implats outlined a R2.7bn restructuring process at its unprofitable Rustenburg operations in August, entailing the removal of up to 13,000 jobs and the closure or sale of five of its 11 mines.

Investors cheered the strongest production performance at the Rustenburg mines in five years, a time before the industry was hit by a five-month strike that stripped one million ounces out of South African platinum output and battered balance sheets.

The news of the job cuts and shaft closures provoked the ire of mineral resources minister Gwede Mantashe and the unions, which urged the company to seek alternatives to shutting mines and shedding jobs.

Implats said on Wednesday that it had started a process to find interested buyers in its 1 Shaft that was scheduled for closure in April 2019. It was also talking to groups that wanted to mine the shaft as a contractor, supplying Implats with ore.

The shaft produced 78,000oz of platinum in the 2018 financial year and it has 2,500 employees and 1,200 contractors. The Rustenburg mines produced 669,000oz of platinum in the 2018 financial year.

One market source said it would be difficult for a buyer to raise capital to buy a deep-level platinum mine that was nearing the end of its life, with Sibanye-Stillwater the only real potential suitor but which has its hands full in finalising a takeover of Lonmin, the world's number three platinum miner, by the end of the year.

As part of its restructuring, Implats was busy with the process of laying off 1,500 people in line with provisions in the Labour Relations Act.

In a production report for the three months to end-September, the first quarter in the company’s 2019 financial year, Implats said a strong performance from its Rustenburg mines had offset reduced output from its Two Rivers joint venture with African Rainbow Minerals and lower toll treatment of third-party material.

The Rustenburg mines returned to production levels last seen in the first quarter of its 2013 financial year, with milled tons of 3.15-million tons in the quarter, the highest since the same period in 2013.

The milled tons were nearly 6% higher than in the same period a year earlier.

Platinum in concentrate was 3% higher at 186,000oz, while refined platinum production shot up 35% to 180,000oz. There was furnace maintenance in the same period a year ago, which lowered refined platinum production then to 133,000oz.

“I am pleased to report improved safety and operational performances during the quarter, particularly at Impala Rustenburg, which has reported its highest first-quarter mill tonnage for the past six years,” Implats CEO Nico Muller said.

“We remain steadfast in our resolve to eliminate high-cost production at this business, aligned with our lower future metal prices outlook,” he said.

The R2.7bn, three-year restructuring plan will cut production to 520,000oz of platinum from the 750,000oz a year the company produces now.

Implats is ramping up two new shafts in Rustenburg that will offset the loss in ore from the closure of shafts over the next three years.

As a group, Implats produced 369,000oz of refined platinum, up from 341,000oz in the same quarter a year earlier. Palladium increased to 207,000oz from 189,000oz while rhodium output was flat at 47,000oz.