The purchaser may award, without prior advertising or competitive tendering, contracts for the performance of services similar to those awarded to the holder of a previous contract awarded after competitive tendering. The first contract must have indicated the possibility of using this procedure for similar services. The call for competition must also have taken into account the total amount envisaged, including that of the new works or services.
The period during which contracts for similar services or works may be concluded may not exceed five years from the notification of the initial contract, except in exceptional circumstances determined by taking into account the expected lifetime of the objects, installations or systems supplied, as well as the technical difficulties which a change of contractor may cause.