The proposed conference contribution studies the role of private actors in European regulatory governance, with a focus on electricity markets. It argues that infrastructure companies provide public goods requiring technical expertise and technically driven cooperation which cannot be delivered by territorially bound public governance. In addition, the scope of required cooperation does often not fit the territorial boundaries public regulators and policymakers encounter – this holds for cross-border cooperation in general, as well as for patterns of regional cooperation. As a result, regulatory governance networks bringing together infrastructure companies, such as the European Network of Transmission System Operators in Electricity (ENTSO-E), play a key role alongside the regulatory networks composed of sector agencies, such as the Agency for the Cooperation of Energy Regulators (ACER). Paying special attention to the case of the ‘energy island’ Switzerland, the paper will also illustrate that private governance is superior to public governance in incorporating non-EU member states where need occurs, and thus allowing for flexible integration. The suggested paper studies the evolution of private governance in European internal and external energy policy, coming to the conclusion that we do not observe a single trend towards more centralized, agency-based steering.