He said the increased productivity was partly attributed to more investment in modernization of the coal industry. In 2011, around US$210 million was invested in an upgrade of the country’s coal mines. The State Statistic Service said Ukraine’s coal output rose 4% year-on-year to 75 million mt in 2010. Ukraine ranks among the world’s top 10 coal mining countries. The nation’s total coal resources are estimated at 52 billion mt with commercial coal reserves at nearly 34 billion mt.