  In the context of supersymmetric seesaw models of neutrino masses with
non-degenerate heavy neutrinos, we show that Dirac Yukawa interactions N^c_i
(Y_nu)_{ij} L_j H_2 induce large threshold corrections to the slepton soft
masses via renormalization. While still yielding rates for
lepton-flavour-violating processes below the experimental bounds, these
contributions may increase the muon and electron electric dipole moments d_mu
and d_e by several orders of magnitude. In the leading logarithmic
approximation, this is due to three additional physical phases in Y_nu, one of
which also contributes to leptogenesis. The naive relation d_mu/d_e\approx
-m_mu/m_e is violated strongly in the case of successful phenomenological
textures for Y_nu, and the values of d_mu and/or d_e may be within the range of
interest for the future experiments.
