It is proved that when 8 fermions associated with the supersymmetries broken by the AdS_4 x CP^3 superbackground are gauged away by using the kappa-symmetry corresponding equations obtained by variation of the AdS_4 x CP^3 superstring action are cont
ained in the set of fermionic equations of the OSp(4|6)/(SO(1,3) x U(3)) sigma-model.
