  We report on a field-induced change of the electronic band structure of
CeBiPt as evidenced by electrical-transport measurements in pulsed magnetic
fields. Above ~25 T, the charge-carrier concentration increases nearly 30% with
a concomitant disappearance of the Shubnikov-de Haas signal. These features are
intimately related to the Ce 4f electrons since for the non-4f compound LaBiPt
the Fermi surface remains unaffected. Electronic band-structure calculations
point to a 4f-polarization-induced change of the Fermi-surface topology.
