The creation of a common European market for financial services has significantly altered the strategic edifice for banks, as well as for the trade unions representing their employees. In the Nordic countries, where regulation of the labour market has long relied on multiemployer bargaining and strong sector-level actors, this has led to a strategic realignment. Faced with mergers and acquisitions, the potential for delocalization and an increasing amount of directly applicable EU-regulation in the sector, Nordic finance trade unions have supported the creation of company-level trade union alliances within MNCs, while still building upon resources and repertoires stemming from Nordic ‘comparative institutional advantage’. Our ‘extended case study’ of three such alliances in the finance sector, called ‘Nordic company clubs’, concludes that, while trade unions there still benefit from strong, typically Nordic institutional and associational power resources, important actor-centred variables and capabilities such as narratives, scaling, resourcefulness and institutional experimentation complement and strengthen our understanding of trade union strategies and institutional change in the context of market integration.