The Triangulation Problem consists in finding a simultaneous permutation of rows and columns of a given square matrix, so that the sum of the upper-diagonal entries is maximal. The researchers study this problem intensively, as it has major applications in broad domains. A new hybrid Ant Colony Optimization algorithm is introduced. The algorithm starts with a greedy search procedure. It is followed by an improved version of the Ant Colony System mixed with a problem-specific local search.<br /><br />