San Diego--Dell Computer Corp., Austin, Texas, said it would create a small business marketplace, using purchasing software and services from Ariba Inc., Mountain View, Calif. The move is a potential blockbuster. Dell, which already dishes custom marketing pages to 40,000 corporate employees, will use its business relationships to sell all sorts of products and services to small businesses. The move makes Dell a potential competitor to already existing small-business exchanges, including market leader Purchase Pro. The move to make the marketplace is part of a sweeping alliance with Ariba, which also includes selling Ariba software already loaded on Dell servers, and an equity stake in Ariba for Dell. Paul Touw, VP-corporate strategy, said Dell's 40,000 personal pages could prove to be a ``Trojan horse,'' allowing Ariba to reach corporations unfamiliar with Internet purchasing for anything other than computers.