SUMMARY. This paper focuses on the antecedents of the form of inter-organisational governance used by U.S. software firms in their relationships with European firms. Specifically, whether the choice between acquisition, investment (joint venture or equity exchange) or contractual agreement is associated with characteristics such as the host country, industrial sector, range of functions covered by the relationship, technological intensity, or year in which the relationship occurred. The influence of these antecedents is investigated using data on 682 relationships between U.S. and European software firms that occurred between 1985 and 1995. The analysis shows that choice of a contractual agreement is almost exclusive, but the relative likelihood of an acquisition or an investment is increased when a relationship involves a larger number of functions. The likelihood of an acquisition is decreased if the European partner is located outside of the U.K., but the likelihood of an investment is increased. Finally, industrial sector, technological intensity and year do not have a significant influence on the choice of alliance form. Possible explanations for these results and their implications for research and managerial practice are discussed. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. 50 E-mail address: <getinfo@haworthpressinc.com> Website: < https://www.HaworthPress.com > © 2001 by The Haworth Press, Inc. All rights reserved.]