RETAILING

May Department Stores to Expand: The St. Louis-based retailer said it plans to invest $5 billion in the next five years to expand and remodel its stores nationwide. The company, whose holdings include the Robinsons-May and Payless ShoeSource chains, said it will open 15 department stores in 1994. The company also said it will open 240 Payless ShoeSource stores and 200 Payless Kids stores nationwide in 1994. Some new stores will be opened in California, the company said. May said it will announce the location of store openings later this year.