  We discuss the ultra-relativistic gravitational scattering of two massive
particles at two-loop (3PM) level. We find that in this limit the real part of
the eikonal, determining the deflection angle, is universal for gravitational
theories in the two derivative approximation. This means that, regardless of
the number of supersymmetries or the nature of the probes, the result connects
smoothly with the massless case discussed since the late eighties by Amati,
Ciafaloni and Veneziano. We analyse the problem both by using the analyticity
and crossing properties of the scattering amplitudes and, in the case of the
maximally supersymmetric theory, by explicit evaluation of the 4-point 2-loop
amplitude using the results for the integrals in the full soft region. The
first approach shows that the observable we are interested in is determined by
the inelastic tree-level amplitude describing the emission of a graviton in the
high-energy double-Regge limit, which is the origin of the universality
property mentioned above. The second approach strongly suggests that the
inclusion of the whole soft region is a necessary (and possibly sufficient)
ingredient for recovering ultra relativistic finiteness and universality at the
3PM level. We conjecture that this universality persists at all orders in the
PM expansion.
