  The effect of a microscopic three-body force on the saturation properties of
nuclear matter is studied within the Brueckner-Hartree-Fock approach. The
calculations show a decisive improvement of the saturation density along with
an overall agreement with the empirical saturation point. With the three-body
force the symmetry energy turns more rapidly increasing with density, which
allows for the direct URCA process to occur in $\beta$-stable neutron star
matter. The influence of the three-body force on the nuclear mean field does
not diminish the role of the ground state correlations.
