The modification of the contractual terms: conventional, judicial or arbitral

The research project will begin with an analysis of the interest of the parties at the time of contracting. This analysis will be carried out not only from a legal point of view but also from an economic and social point of view. After that, the possible reasons why the interest of the parties may be diminished or modified during the contractual execution will be exposed to finally analyze the possibility that the parties have to renegotiate the contractual terms and in the absence of a subsequent renegotiation agreement, verify whether the jurisdictional body (judicial or arbitral) can adjust the contract in order to restore the interest of the parties and the contractual balance.

In long-term contracts, the execution period can often influence the legal position and the interest of the contracting parties. This should not be a matter of renegotiation of the contractual terms, since each contracting party adopts a series of risks at the time of contracting. But many times the events that can bring about the alteration of the benefits that the party had thought to obtain when contracting are events outside the sphere of control of the interveners. That is, events that are outside the scope of the business and/or that could not have been reasonably foreseeable by the parties. These can cause the benefits to become excessively onerous for the parties and therefore the expected benefit is less or null or even the contracting party loses with the execution of the contract.
Article 1440 of the Civil Code provides the following possibilities: i) reduction or increase of the consideration or ii) termination of the contract. This last assumption will be granted by the Judge whenever the counterpart requests it or due to the nature of the benefit or the circumstances of the case. The problem with this regulation is that the counterparty sued in a process for excessive onerousness will always request the resolution of the contract before increasing its consideration or seeing the plaintiff's benefit reduced. This generates that the judges - despite the principle of conservation of the contract - must opt ​​for its resolution.