The recent reform of the Italian National Health Service brings to the fore some new problems in establishing public-private corporations. This is because producers are introduced in a network where each of them is assigned a monopolistic position. This shifts antitrust concerns from ensuring some freedom of choice for the patients to designing institutions that guarantee some competition to enter the network. To avoid dominant positions, purchasers of health services should examine the comparative advantage of different mechanisms that may provide greater long-terms efficiency and a more favourable allocation of financial risks.