MarketMAX Inc., Chicago, debuted Saturday an Internet portal that's designed to provide trading services to manufacturers of retail store shelves and other store-related products. The site, announced at the GlobalShop 2000 trade show in Chicago, provides online catalogs, virtual showrooms and chat services to retailers building and upgrading stores. Lori Schafer, president and CEO of MarketMAX, Danvers, Mass., said the site should bridge the gap between retail marketing managers and store operators. Products to be featured on the portal include store shelves and point-of-purchase advertising supplies. MarketMAX also will facilitate the transfer of large digital files used in designing and building stores for its customers.