Paper/Speech Details of Conference Program for the 18th NISPAcee Annual Conference Program Overview IV. Working Group on PA Reform Author(s) Iwona Sobis Goteborg University Göteborg Sweden de Vries Michiel, Michiel S. de Vries Title Restoring professionalism:What can public administration learn from theories on inter-organizational behaviour? File Paper files are available only for conference participants, please login first. Presenter Abstract The last two years we were focusing on the issue of professionalism when providing technical assistance to CEE countries during their transition to a market economy. In conformity with Brint's classification, we have identi-fied two types of professionals in the western aid-business i.e., trustee-professionals and expert-professionals. Although we saw a massive exit of trustee professionals, we have been advocating the return of these trustee-professionals in organizations (See Sobis and & De Vries, 2009). This paper addresses the question what theories on inter-organizational behaviour tell us what to do to improve performance. What do these theories tell about managing complex projects and what clues it gives to accom-plishing cooperation between trustee-professionals in such a network? We talk about complex networks, because a.o. members of such networks are not necessary coming from one and the same organization. Opposite, they are recruited from different organizational settings and they create project together and an organization in itself. This paper departs from inter-organizational theory. What can public administration learn from these theories and what do such theories tell about optimal steering of professionals. Thus, the paper is rather theoretical in its character. It starts with an overview of the aforementioned theories and continues with the lessons learned from them. It is concluded by a critical reflection on the theories and the suggestions following from it.