THE COUPON Clearing Association is in disarray after the resignation of its two leading members, NCH Marketing Services and Kersten Promotions. Their abrupt exit follows a row with the CCA committee over the proposed sharing of sensitive information on the latest coupon processing techniques - something the secretive duo claim would undermine their competitive advantage and lead to loss of market share. Says US-owned NCHMS: 'We are a heavy investor in new technology and have no intention of sharing that with anybody.' But CCA chairman Peter Kerr, who is also managing director of rival clearer MRM Promotional Services, insists the Association's aim is simply to cut-down on double-processing of coupons, once by the retailer and again by the manufacturer - or a clearing house on the manufacturer's behalf: 'Culturally and spiritually, we should not suppress new technology if it's for the benefit of the industry', Kerr said, in a mix of idealism and metaphysics infrequently met in clearing house circles.