• 1 Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires]
• 2 Departamento de Computación [Buenos Aires]
• 3 Departamento de Matemática [Buenos Aires]
• 4 Departamento de Ingenieria Industrial [Santiago]
• 5 Instituto de Cálculo [Buenos Aires]
• 6 Laboratoire d'Informatique, de Modélisation et d'optimisation des Systèmes
• 7 Université Blaise Pascal - Clermont-Ferrand 2

A graph is balanced if its clique-vertex incidence matrix contains no square submatrix of odd order with exactly two ones per row and per column. There is a characterization of balanced graphs by forbidden induced subgraphs, but no characterization by mininal forbidden induced subgraphs is known, not even for the case of circular-arc graphs. A circular-arc graph is the intersection graph of a family of arcs on a circle. In this work, we characterize when a given graph G is balanced in terms of minimal forbidden induced subgraphs, by restricting the analysis to the case where G belongs to certain classes of circular-arc graphs, including Helly circular-arc graphs, claw-free circular-arc graphs, and gem-free circular-arc graphs. In the case of gem-free circular-arc graphs, analogous characterizations are derived for two superclasses of balanced graphs: clique-perfect graphs and coordinated graphs.