A problem of competition between the three largest banks of the Mongolia major crediting sector is investigated. Modeling of the conflict is carried out using the apparatus of three person polymatrix games (hexamatrix games). To find a Nash equilibrium in the constructed game we use an approach based on its reduction to a nonconvex optimization problem with bilinear structure in the objective function. To solve the latter problem we apply Global Search Theory due to A. S. Strekalovsky. According to the theory, local and global search algorithms for formulated game are developed. Local search method is based on the idea of sequential solving of auxiliary linear programming problems followed from the formulation of the problem. Global search based on a specific Global Search Strategy in the d.c. maximization problems as the objective function of the reduced optimization problem can be represented as a difference of two convex functions. The results of a computational simulation is presented and analized.

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