Anglo American posted a record operating profit of $11.1 billion in 2011. In that year it paid $5.1 billion for the Oppenheimer family's 40 percent stake in De Beers, raising Anglo's stake to 85 percent.In the first half of this year, operating profit slumped by 38 percent and net profit fell 70 percent as the group was hit by lower commodity prices and higher costs. Anglo American also became embroiled in a dispute with Chile when it announced in 2011 that it had agreed to sell its 24.5 percent stake in Anglo American Sur, its copper assets in Chile, to Mitsubishi for $5.4 billion. That sale was challenged by Codelco, Chile's state-owned copper miner, which had an option to take a 49 percent stake. Codelco and Anglo American resolved the dispute in August as Anglo reduced its holding in AA Sur from 75.5 percent to 50.1 percent, while a Codelco-Mitsui joint venture took a 29.5 percent interest. Anglo American's operations in South Africa have been set back by labor unrest since September, when more than 10,000 miners at Anglo American Platinum's operations outside Johannesburg went on strike demanding 16,000 rand (about $1,800) in monthly pay. Amplats, the world's top producer of platinum, insisted the strike is illegal. The company fired 12,000 workers en masse earlier this month, drawing condemnation from the influential Congress of South Africa Trade Unions, COSATU. COSATU has called for a massive street protest Saturday in support of the dismissed workers, who have threatened to make the company's operations ungovernable if they are not reinstated. Mpumi Sithole, a spokeswoman for Amplats, said Thursday that the company stands by its decision to fire the workers. ___ Andrew Meldrum in Johannesburg contributed to this report.