  We determine the localization threshold in a partially filled and orbitally
degenerate model of correlated electrons. Particular emphasis is put on a
non-integer band filling, when the system decomposes into the localized and the
itinerant subsystems; this situation is described by an effective s-d model. A
simultaneous transition to the ferromagnetic state is discussed as driven by
the Hund's rule coupling. Dependence of the quasiparticle mass on the spin
direction appears naturally in the ferromagnetic phase and is attributed to the
electron correlation effects, as is also a metamagnetic transition in an
applied field. Although the main results have been obtained within the saddle
point slave-boson approach, their qualitative features are discussed in general
terms, i.e. as a transition from quantum-mechanical indistinguishability of
particles to the two-component situation. A comparison with the situation for
the orbitally nondegenerate band is also briefly mentioned.
