SANTIAGO, Aug 5 (Reuters) - Chile's government forecast on Monday that the world's No. 1 copper producer will attract more mining investments of some $112 billion in the next eight years. The estimate, which is higher than the previous forecast in November of $104 billion in investments, "is due to the incorporation of nine new projects for a total of $3.6 billion and another 20 initiatives (projects) that have updated their investment budgets," Mining Minister Hernan de Solminihac said. In January, the Sonami mining association said it expected Chile to get $100 billion in mining investment over the next 10 to 12 years, a slightly longer timeframe than previously forecast, as regulatory uncertainty and energy woes are key risks. Chile's annual production capacity will increase to 8.1 million tonnes of refined copper in 2021 considering the current investment portfolio, from 5.9 million tonnes last year, Solminihac said. But actual copper output in the coming years may be lower than capacity due to "contingencies in the sector," he added. Though the Andean nation is seeking to boost output at its giant, ageing mines, a mix of sliding grades, soaring costs, labor unrest, energy woes and legal setbacks to mining projects could curb its ambitious plans. In 2012, Chile boosted its copper production by 3 percent to 5.455 million tonnes. Among companies helping to boost the overall investment estimate, state miner Codelco, the globe's biggest copper miner, expects to boost its annual investment to an all-time high of more than $5 billion this year, from about $4 billion in 2012. Codelco is aiming to produce more than 2 million tonnes of the red metal by 2021, a big leap from less than 1.7 million tonnes last year, and to do so it has launched an ambitious long-term investment plan of about $28 billion. Mining sector dynamism helped economic activity in Chile to beat forecasts and expand 4.2 percent in June from the same month a year ago, data showed earlier on Monday. Copper accounts for over half of all Chilean exports.