We propose a new method for implementing conservative forces in a dissipati
ve particle dynamics (DPD) system. We allow multibody interactions, and use
information on the macroscopic equilibrium behaviour of the system. We sho
w that it is then possible to induce a fluid/fluid phase transition, and al
so that the local structure is then less pronounced than in previous models
. This last feature is desirable in the description of fluids at a mesoscop
ic scale.