Kazakhstan said Friday it plans to work with two Japanese companies to become the world\'s top uranium producer within five years. State-owned KazAtomProm will work with Sumitomo Corp. and Kansai Electric Power Co. to increase Kazakh uranium yearly output from 4,000 tons to 15,000 tons, thus exceeding the production of Canada\'s Cameco Corp., the world\'s current top uranium producer, KazAtomProm said in a statement. The company\'s head, Mukhtar Jakishev, said KazAtomProm planned to spend about $600 million building new mines and upgrading existing ones. KazAtomProm is also negotiating such projects with the China National Nuclear Corp. and has plans to establish a joint venture with South Korean companies Korea Hydro & Nuclear Power Co. and Korea Resources Corp. (UPI)