This paper analyses whether and how business-to-business (B2B) e-commerce applications might increase access to the global economy for firms in developing and transitional economies. E-marketplaces are considered according to two variables: the extent to which access to the marketplaces are open or restricted, and the extent to which the marketplace is focused on online transactions or provision of information. The paper highlights how different types of e-marketplaces address the issues of the reduction of search costs, co-ordination of the activities of buyers and sellers and containment of the risks posed by opportunistic behaviour. It concludes that transaction-oriented, open e-commerce marketplaces are likely to be less important for firms in developing countries firms than both open, information-oriented marketplaces and private and industry-sponsored marketplaces. Policies aimed at promoting B2B e-commerce in developing country firms will need to be tailored to these different types of marketplaces.