espanolEl convenio arbitral reside, por naturaleza, en la voluntad de las partes de someter sus controversias al fuero arbitral, renunciando a la jurisdiccion ordinaria. Sin embargo, en el marco de los contratos publicos, el convenio arbitral no presenta las notas de voluntariedad que existen en los contratos privados, precisamente por la naturaleza publica de la entidad contratante, lo que significa que esta se sujeta al principio de legalidad, no teniendo autonomia de la voluntad. En este trabajo se pretende demostrar que, como consecuencia de ello, se producen convenios arbitrales desequilibrados a favor de las entidades publicas que predisponen su contenido. En efecto, la inexistente posibilidad del contratista de determinar el contenido del convenio arbitral tiene como efecto que la entidad contratante predisponga su contenido, de manera tal que le beneficie de forma desproporcionada en detrimento del contratista, provocando una situacion ineficiencia. El legislador, consciente de ello, ha dispuesto progresivamente reglas que buscan otorgar mayores derechos al postor y restringir la discrecionalidad de la entidad; sin embargo, dichas medidas no parecen ser suficientemente satisfactorias. En dicho contexto, se propone una respuesta desde la intervencion legal en el contenido del referido convenio, de manera que se asegure, desde su regulacion ex ante, que el contenido del convenio arbitral sera equilibrado. EnglishThe arbitration agreement has its origin, by nature, in the free will of the parties who want to summit their controversies to arbitration, instead of the ordinary jurisdiction. However, in the case of the public contracts, the arbitration agreement does not have the same characteristics of free will, as they have in civil contracts, precisely because of the public nature of the authority, which means that they are subject to the legality principle instead of having free will. In this paper I will try to prove that, as a consequence of it, our legal framework produces one-sided arbitration agreements which benefit the public authorities who draft those agreements. In fact, the lack of possibilities for the contracting party to negotiate the content of the agreement allows the public authority to draft such content in a way that only benefit them and negatively affects the contractor, creating a situation of inefficiency. The legislator, aware of the problem, has enacted rules that seek to recognize rights to the bidder and restrict the discretionary powers of the authority; however, those measures are not good enough. In this scenario, I propose a solution which requires legal regulation in the content of the aforementioned agreements, in a way that can be granted, from an ex-ante regulation, that the arbitration agreement will be balanced.