NEW YORK - Chinese vitamin C manufacturers on May 13 opposed the imposition of a permanent injunction in a case in which a jury previously determined that the manufacturers violated the Sherman Act by participating in a cartel to fix prices and limit supply for exports of vitamin C to the United States (In re Vitamin C Antitrust Litigation $(Animal Science Products, Inc., et al. v. Hebei Welcome Pharmaceutical Co. Ltd., et al.$), No. 06-md-1738, No. 05-cv-0453, E.D. N.Y.).