Organizations do not just decide on whether or not to exchange information digitally. In many cases, there are multiple alternative configurations of inter-organizational systems (IOS) that facilitate such information sharing. Although a lot is known about the factors that influence whether organizations do or do not adopt IOS, little is known about how these factors work when organizations are choosing among multiple configurations for information sharing. This paper takes two archetypical IOS forms - dyadic and multilateral arrangements – and explores how the known antecedents affect choosing among them. To this end, a case study was conducted on the selection and development of an IOS for information sharing in a network of utility service and infrastructure providers.