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South African miners at two platinum mines owned by Anglo American PLC’s Anglo American Platinum subsidiary (known as Amplats) have begun a wildcat strike, demanding that the company lift its suspension on 19 union shop stewards. This latest strike is one of several that have hit Anglo American and Lonmin in the past year.

Amplats has proposed a plan to lower its costs by cutting up to 6,000 jobs and chopping production by about 250,000 ounces in 2013 and another 100,000 ounces annually in each of the next few years, according to a report in the Financial Times.

U.S. platinum miner Stillwater Mining Co. (NYSE: SWC), which recently ousted its chairman and CEO following a proxy fight, has gained more than 4% this morning. Demand for platinum and palladium, another Stillwater mineral resource, is rising as more new cars with new catalytic converters are being made and sold.

Stillwater also operates a platinum recycling plant, which should help the company meet demand for platinum without having to produce more. That will help keep its costs lower and should help improve its profits. Platinum prices have dropped from more than $1,500 an ounce in early June to around $1,360 an ounce.

Stillwater shares are trading at $11.12 in the late morning today, up 4%, in a 52-week range of $7.47 to $14.87.