  We consider a supersymmetric SO(10) model which remains renormalisable upto
Planck scale. The cosmology of such a model passes through a Left-Right
symmetric phase. Potential problems associated with domain walls can be evaded
if parity breaking is induced by soft terms when supersymmetry breaks in the
hidden sector. The smallness of this breaking permits a brief period of
domination by the domain walls ensuring dilution of gravitinos and other
unwanted relics. The requirement that domain walls disappear constrains some of
the soft parameters of the Higgs potential.
