We report the effect of hydrostatic pressure up to 8 kbar on magnetoelastic, magnetic, and transport properties in the temperature range 10–300 K. An increase of Curie temperatureTcwith pressure &Dgr;Tc/&Dgr;p=2.6 K/kbar was determined from ac susceptibility measurements. The anomalies in resistivity and magnetovolume effects are significantly suppressed by pressure but the temperatures of these anomalies increased with pressure with the same slope asTc. These results indicate that impurity state of yttrium rather than lattice parameter reduction is responsible for the large increase in the magnetoresistance observed in the doped compound. ©1995 American Institute of Physics.