Transnational corporations (TNCs) and public enterprises have been perceived as organisations evolving in separate, even antagonistic, business, economic and ideological spheres. Yet, at the beginning of the C21st, utilities in energy, telecommunications, transport and water unexpectedly emerged as leading TNCs. How and why did this remarkable and unprecedented transition occur? What are the consequences for competition, regulation, public services and consumers? Leading authorities from Europe, Russia, Canada, Mexico and the United States analyse the business, economic and historical contexts that have influenced these changes.