RPT-UPDATE 2-Indonesia ships first metal concentrate since January halt

(Fixes formatting, text unchanged) By Wilda Asmarini JAKARTA, July 18 (Reuters) - Indonesia has resumed some exports of metal ore concentrates after two firms gained permits to ship iron ore, zinc and lead, a mining ministry official said, the first shipments of their kind since the country changed its export rules in January. The rule change, which banned unprocessed ore exports and levied an escalating tax on metal concentrate shipments, was part of a policy to force miners to buil