  We consider a class of N=1 supersymmetric extensions of the Standard Model in
which the soft breaking sector is CP conserving at the GUT scale. We study the
question of whether the presence of explicit CP violation in the Yukawa sector
of the theory induces through renormalization effects CP violating phases in
the soft terms, which could lead to observable effects. A clear pattern appears
in the structure of phases in the soft sector. In particular, the inclusion of
intergenerational mixing induces large phases in the flavour mixing entries of
the trilinear soft breaking terms, whereas the diagonal entries remain real. A
mechanism is proposed for generating through chargino exchange a contribution
to the neutron electric dipole moment which can be a few orders of magnitude
larger that that of the Standard Model, although still out of reach of
experimental tests. We comment on the possible relevance of these phases for
baryogenesis at the weak scale in minimal supersymetric scenarios, recently
considered in the literature.
