Purpose: A review of extant literatures shows that most mergers fail during the integration process. Little is known about how the realization of operating synergies and dissemination of available know-how in the merged firm are managed in the post-merger phase. We provide insights on the process of integrating operating synergies by focusing on the critical success factors that facilitate integration of the skills of merged banks.

Design/methodology/approach: We draw on three research traditions in merger literature and reconcile them with three dimensions of integration. In-depth interviews were conducted with Nordea bank’s managers from four Nordic countries.

Findings: Having learned from the mistakes of previous mergers, Nordea’s “guiding star” for managing its post-merger integration process was expressed as Focus, Speed and Performance from top management. Therefore, a hands-on leadership style, vision-led thinking, a bias for action, involvement of the entire staff, continuous focus on customers, and open and honest communication with employees are critical to success.

Concluding remarks and implications: We conclude that the motive for a merger has an important impact on the degree of interaction and degree of integration. This study expands on previous findings by, among other things, synthesizing three theoretical lenses into an integrative model, and addresses post-merger issues with a sharp eye toward clear managerial relevance.

Originality and value: We respond to the call to expand inter-firm relationships study beyond the narrow dyadic relationship focus and not solely conceptualize mergers as one of companies’ entry modes to implement mechanistic growth strategy. The three dimensions of integration imbued with three research traditions in merger literature provides us with a conceptual lens to conceive mergers also as engines for change emerging from the merged firms to enhance a bespoke performance of their business process. Building on this premise in line with our research questions, the focal study broadens the analytical toolbox for radical and incremental change dichotomies identified in prior studies.