The aim of this chapter is to analyse the role of trade unions in decentralised collective bargaining, specifically regarding trade union and works council participation in and influence on the processes and outcomes of collective bargaining at company level. To identify and explain differences and similarities in trade union and works council practice regarding company-level collective bargaining, the authors use an analytical framework based on the power resources approach and focus on structural, associational, and institutional power. The analysis suggests a degree of interchangeability in these power resources. Structural power resources are, for example, important for the outcomes of company bargaining, however, institutional and associational power resources may complement the lack or presence of such structural power resources.