Potential energy surfaces for the O(D-1) + N2O reaction have been calculated using multiconfiguratonal second-order perturbation theory (CASPT2) with Dunning's correlation-consistent polarized valence double-zeta basis set. It has been found that a wide range of the O(D-1)-N-N approach angles from collinear to nearly perpendicular configurations is attractive on the lowest (1)A' surface. The calculations show that the height of the exit barrier for the NO + NO production is strongly dependent on the O(D-1)-N-N angle. This suggests that the dynamics of the NO + NO channel is significantly affected by both the initial approach and subsequent bending motion of the O(D-1)-N-N angle. The reaction mechanism for the O-2 + N-2 production channel is also discussed.