13 6) In the other cases provided for in this Law. It shall also be lawful for the parties, at the request of the author, to convert the rights deriving from the contracts currently in force into lump-sum annuities for periods to be decided on by the parties. Article 64 – In the event of the assignment of an exploitation right, where the author has suffered loss or damage of over seven-twelfths as a result of damage or an underestimation of the anticipated proceeds from the work, he may prompt a review of the conditions in the contract relating to price. This request may be made only in cases where the work has been assigned for payment of a lump sum. The injury shall be estimated taking into consideration the full extent of the exploitation by the assignee of the works of the author who claims to have been adversely affected. Article 65 – The clause in a deed of assignment intended to confer the right to exploit the work in a form unforeseeable or unforeseen on the date of the contract must be express and a correlative share of the profits from the exploitation must be stipulated. Article 66 – In the event of a partial assignment, the successor in title shall substitute for the author in the exercise of the rights assigned, in the conditions, within the limits and for the period specified in the contract, and is obliged to provide a report. Article 67 – With a view to the payment of the royalties and the remuneration due to them for the previous three years on the occasion of the assignment and the exploitation or use of their works, as defined in Article 5 of this Law, authors, composers and artists shall enjoy the privilege provided for in paragraph 4 of Article 2101 and Article 2104 of the Civil Code. CHAPTER II Provisions peculiar to certain contracts SECTION I Performance contract Article 68 – A performance contract is one whereby the author of an intellectual work and his successors in title authorize a natural person or legal entity to represent the said work on conditions decided on by them. A general performance contract is one whereby the body referred to in Article 124 confers on an exploiting party the power to perform, for the period of the contract, the present or future works, constituting the repertoire of the said body on the conditions laid down by the author or his successors in title. In the situation provided for in the preceding paragraph, an exception may be made to the provisions of Article 60. Article 69 – A performance contract is entered into for a limited period or for a specific number of communications to the public. Save where exclusive rights are expressly provided for, it shall not confer on the impresario any monopoly on exploitation. The period of validity of the exclusive rights granted by a dramatist cannot exceed five years; the suspension of performances for two consecutive years shall automatically end it. An impresario cannot transfer the benefit of his contract without formal consent given in writing by the author or his representative.