The global refined lead market is expected to be in surplus by 123,000 tonnes in 2011, the International Lead and Zinc Study Group, or ILZSG, said on Thursday. The forecast gap is larger than the 48,000-tonne surplus in 2010. Demand for refined lead is forecast to increase by 5.5 per cent to 10.04 million tonnes in 2011, while world production is expected to be 10.16 mt, 6.1 per cent higher than the year before, the ILZSG said. This increase in production will be largely due to an expected 7.8 per cent increase in global lead mine production to 4.46 mt this year, driven primarily by higher output in China, Australia, India, Ireland, Mexico and the Russian Federation, the ILZSG said.