New York stores selling brand-name products not intended for sale in the United States will be required, starting next week, to warn consumers when manufacturers' warranties are invalid. The "gray market" disclosure law is the first requirement of its kind in the nation, state Atty. Gen. Robert Abrams said. "It advises consumers that, in exchange for a substantially cheaper price on brand-name goods, they will not receive the manufacturer's warranty, be eligible for a manufacturer's rebate and may not have instructions in English." All stores in New York selling the gray market products must post signs and places an advisory in their advertising, telling consumers before they make a purchase that the goods are imported on the gray market.