  Magnetotransport properties in a nanocrystalline
La$_{0.67}$Sr$_{0.33}$MnO$_{3}$/micron sized Al$_{2}$O$_{3}$ granular composite
with different concentrations of Al$_{2}$O$_{3}$ have been studied. The
resistivity curves in absence of magnetic field and the various transport
mechanisms which might account for the upturn in resistivity at low
temperature, has been discussed. Enhancement of low field magnetoresistance at
room temperature with the introduction of Al$_{2}$O$_{3}$ has been observed.
