LONDON, June 3 (Reuters) - Indonesia has emerged as the world’s dominant producer of nickel over the last 10 years. Mined production last year was 771,000 tonnes, twice as much as the world’s second largest producer the Philippines and accounting for almost a third of global output, according to the International Nickel Study Group (INSG). It is only going to grow further as investment, particularly from China, floods into Indonesia’s nickel sector. National output could exceed a million tonnes this year and, according to Macquarie Commodity Strategy consultant Jim Lennon, will reach more than 2.5 million tonnes by the end of the decade, at which point it will have exceeded last year’s global production.