  We introduce a method to extract the symbol of the coefficient of $(2\pi
i)^2$ of MHV remainder functions in planar N=4 Super Yang-Mills in multi-Regge
kinematics region directly from the symbol in full kinematics. At two loops
this symbol can be uplifted to the full function in a unique way, without any
beyond-the-symbol ambiguities. We can therefore determine all two-loop MHV
amplitudes at function level in all kinematic regions with different energy
signs in multi-Regge kinematics. We analyse our results and we observe that
they are consistent with the hypothesis of a contribution from the exchange of
a three-Reggeon composite state starting from two loops and eight points in
certain kinematic regions.
