Using an original database concerning 1102 French local public authorities in 2001, we explore the relationships between prices charged by private operators in water contracts and ex post competition. We show that prices charged in contracts in which operators are in a monopoly situation throughout the duration of the contract, are not affected by a ‘competition effect' between private operators. However, a competition effect between private operators and public management appears to be crucial in explaining prices combined with a ‘termination effect', reflecting the fact that the contract is close to being renewed, and hence re-auctioned.