  We investigate the role of CP phases within the renormalizable SUSY SO(10)
GUT with one 10_H, one 126bar_H one 126_H and one 210_H Higgs representations
and type II seesaw dominating the neutrino mass matrix. This framework is non
trivially predictive in the fermionic sector and connects in a natural way the
GUT unification of b and tau Yukawa couplings with the bi-large mixing scenario
for neutrinos. On the other hand, existing numerical analysis claim that
consistency with quark and charged lepton data prevents the minimal setup from
reproducing the observed CP violation via the Cabibbo-Kobayashi-Maskawa (CKM)
matrix. We re-examine the issue and find by inspection of the fermion mass sum
rules and a detailed numerical scan that, even though the CKM phase takes
preferentially values in the second quadrant, the agreement of the minimal
model with the data is actually obtained in a non negligible fraction of the
parameter space. We then consider a recently proposed renormalizable extension
of the minimal model, obtained by adding one chiral 120-dimensional Higgs
supermultiplet. We show that within such a setup the CKM phase falls naturally
in the observed range. We emphazise the robust predictivity of both models here
considered for neutrino parameters that are in the reach of ongoing and future
experiments.
