  In the framework of two-point sum rules of NRQCD, the masses and couplings of
doubly heavy baryons to the corresponding quark currents are evaluated with
account of coulomb-like corrections in the system of doubly heavy diquark as
well as the contribution of nonperturbative terms determined by the quark,
gluon, mixed condensates and the product of gluon and quark condensates. The
introduction of nonzero light quark mass destroys the factorization of baryon
and diquark correlators even at the perturbative level and provides the better
convergency of sum rules. We estimate the difference M_Omega - M_Xi = 100+/- 10
MeV. The ratio of baryonic constants |Z_Omega|^2/|Z_Xi|^2 is equal to 1.3+/-0.2
indicating the violation of SU(3) flavor symmetry for the doubly heavy baryons.
