At a time when higher education institutions are increasingly expected to demonstrate societal relevance, it is pertinent to examine why specific structural configurations are chosen to carry out that task. Based on a comparative case study of three merged higher education institutions in Norway, this article examines the three new HEIs' rationales for and attempts at constructing and maintaining their relations with external stakeholders. The findings illustrate that the type of merger, size and geographical spread of campuses all matter in this regard. Based on our results, a finer-grained set of categories is proposed for mapping the structural configurations of organisations in support of regional engagement and third mission activities. These highlight the importance of identifying positions, arenas, formal agreements and oversight and coordination activities.