  A smooth cut-off formulation of the Hierarchical Reference Theory (HRT) is
developed and applied to a Yukawa fluid. The HRT equations are derived and
numerically solved leading to: the expected renormalization group structure in
the critical region, non classical critical exponents and scaling laws, a
convex free energy in the whole phase diagram (including the two-phase region),
finite compressibility at coexistence, together with a fully satisfactory
comparison with available numerical simulations. This theory, which also
guarantees the correct short range behavior of two body correlations,
represents a major improvement over the existing liquid state theories.
