  Models of the universe with arbitrary (non gravitational) interaction between
the components of the cosmic fluid: the phantom energy and the background, are
investigated. A general form of the interaction that is inspired in
scalar-tensor theories of gravity is considered. No specific model for the
phantom fluid is assumed. We concentrate our investigation on solutions that
are free of the coincidence problem. We found a wide region in the parameter
space where the solutions are free of the big rip singularity also. Physical
arguments, together with arguments based on the analysis of the observational
evidence, suggest that phantom models without big rip singularity might be
preferred by Nature.
