The low-doped magnetic perovskite La 7/8 Sr 1/8 MnO 3 undergoes within the paramagnetic-semiconducting phase a first-order structural transition due to antiferrodistorsive ordering of Jahn-Teller deformed MnO 6 octahedra. This allows us to study not only the influence of the spin configuration on the magnetotransport properties colossal magnetoresistance CMR effect but also the role of orbital order and disorder. The orbital ordering transition at 269 K in zero magnetic field causes a doubling of the resistivity regardless of the CMR effect in applied magnetic fields and a drop of the paramagnetic susceptibility. The latter might be interpreted in terms of a shrinking of spin polarons. External magnetic fields shift the ordering transition to lower temperatures according to the field-induced decrease of the carrier localization. The magnetic-field-temperature phase boundary line was investigated by means of magnetoresistance up to 12 T and pulsed-fields magneti-zation measurements up to 50 T. The pronounced magnetization anomalies, associated with the phase transition , vanish for fields exceeding 20 T. This behavior has been attributed to a field-induced crossover from antiferrodistorsive order to a nondistorsive/ferromagnetic orbital configuration.