This thesis investigates relations between five Russian energy companies – RAO UES/Inter RAO (electricity), Minatom/Rosatom (nuclear energy), Lukoil (oil), Transneft (oil pipelines) and Gazprom (gas) – and the Russian state from 1992 to 2012, with particular regard to state-company interaction over Russian foreign policy and companies’ activities in the post-Soviet region. The argument is that, due to the institutional legacies of the Soviet system, state-company interaction over foreign policy and energy operations abroad was part of their interaction over the Russian state’s institutional development. The study is based on the conceptual framework of social orders developed by North, Wallis and Weingast (NWW). State-company relations are seen to vary according to their informality and formality, and how closely the companies, and their rent streams, are tied to the state and the ruling coalition, or regime. The thesis concludes that the institutions that structure companies’ relations with the Russian state at home make them more or less available as foreign policy tools. In particular, domestic state-company relations influence the companies’ role in maintaining post-Soviet energy dependence on Russia. The thesis highlights the energy companies’ importance for state infrastructural power, and for the durability of Russia’s authoritarian regime.