  The poor man's scaling is extended to higher order by the use of the
open-shell Rayleigh-Schroedinger perturbation theory. A generalized Kondo-type
model with the SU(n) times SU(m) symmetry is proposed and renormalized to the
third order. It is shown that the model has both local Fermi-liquid and
non-Fermi-liquid fixed points, and that the latter becomes unstable in the
special case of n=m=2. Possible relevance of the model to the newly found phase
IV in Ce_{x}La_{1-x}B_6 is discussed.
