  In general the onset of hybrid inflation requires an extremely homogeneous
field configuration at the end of Planck era. The field \phi orthogonal to the
inflaton \sigma must be zero with high accuracy over the range exceeding the
initial horizon size \sim m_{Pl}^{-1} by about two orders of magnitude. We
consider a supersymmetric model that permits the decay of the oscillating field
\phi into light particles. We study the field evolution and find that the
requirement of the extreme homogeneity can be relaxed. However, the field \phi
must still be smaller than the inflaton by a factor of order 1 over a region
far exceeding the initial horizon size.
