LONDON (Reuters) – Glencore produced 18% less zinc in the first nine months compared with the same period a year before, the company said on Friday as it trimmed its full-year output forecast by 6% due to knock-on effects of the Ukraine war. The forecast reduction was due to “emerging supply-chain issues in Kazakhstan as the secondary impacts of the Russia/Ukraine war are felt”, the commodities group said. Kazakhstan has large deposits of zinc and other materials and Glencore controls Kazzinc, a producer of zinc, copper and lead, in the country. Zinc production of 699,600 tonnes from Glencore’…