[en] We discuss the scaling laws of both the charged fragments multiplicity n fluctuations and the charge of the largest fragment Z_max fluctuations for Xe+ Sn collisions in the range of bombarding energies between 250 A x MeV and 50 A x MeV. We show at E_lab ∼ 32 MeV/A the transition in the fluctuation regime of Z_max which is compatible with the transition from the ordered to disordered phase of excited nuclear matter. The size (charge) of the largest fragment is closely related to the order parameter characterizing this process. (authors)