ZINC PRODUCERS APPROACH EC ON VOLUNTARY CLOSURES A number of individual zinc producing companies have approached the European Commission to sound out its reaction to a possible industry plan for a voluntary reduction of smelting capacity, Commission sources said. The companies have been told that the Commission could not judge whether a plan would be acceptable under European Community, EC, competition rules until it had full details, they said. In 1983, the industry drew up a plan envisaging the loss of about 130,000 tonnes of annual capacity, or about 10 pct of the total. However, the industry did not proceed with this plan as zinc market conditions improved in 1984, the sources noted. They said the companies which approached the Commission recently -- and which they did not name -- appeared to envisage a loss of productive capacity similar to that proposed in 1983.