Custodial supersymmetry in non-supersymmetric quiver theories

We consider non-supersymmetric quiver theories obtained by orbifolding the N=4 supersymmetric U(K) gauge theory by a discrete Z_\Gamma group embedded in the SU(4) R-symmetry group. We explicitly find that in such theories there are no one-loop quadratic divergences in the effective potential. Moreover, when the gauge group U(n)^\Gamma of the quiver theory is spontaneously broken down to the diagonal U(n), we identify a custodial supersymmetry which is responsible for the fermion-boson degeneracy of the mass spectrum.