JOHANNESBURG (Reuters) - Anglo American Platinum swung back to profit in the last year but its earnings recovery is threatened by fresh labour unrest across South Africa's platinum belt. Amplats, the world's largest producer of the precious metal, said on Monday it had headline earnings per share of 556 cents in 2013, a sharp recovery from a year earlier when it booked a loss of 562 cents per share on a wave of violent wildcat strikes. Headline earnings per share is the main profit gauge in South Africa and excludes certain one-off and non-trading items. Amplats did not declared an annual dividend for 2013. Maintaining profit for the company, which is 80 percent-owned by resources giant Anglo American, will be tough after workers went on strike over pay last month. Members of the hardline Association of Mineworkers and Construction Union (AMCU) walk out at Amplats, Impala Platinum and Lonmin on January23, demanding that monthly wages be more than doubled to 12,500 rand. The strike has hit around 40 percent of the global supply of platinum, used in catalytic converters in cars. Amplats said it planned to keep its baseline production flat at a range of 2.3 and 2.4 million ounces in 2014.