  We examine the phase structure of pure Regge gravity in four dimensions and
compare our Monte Carlo results with $Z_2$-link Regge-theory as well as with
another formulation of lattice gravity derived from group theoretical
considerations. Within all three models we find an extension of the
well-defined phase to negative gravitational coupling and a new phase
transition. In contrast to the well-known transition at positive coupling there
is evidence for a continuous phase transition which might be essential for a
possible continuum limit.
