Final states indicating the presence in the reaction of three-body fragment
ation processes has been observed in S-32+Co-59 and S-32+Cu-63 dissipative
collisions at 5.6 A.MeV. Besides the already observed sequential binary pro
cess, data analysis reveals the presence of prompt ternary break-up of the
composite system. Indications on the system configuration at the scission h
ave been deduced by analyzing the event shape in the momentum phase space.
The decay appears to occur in a collinear configuration, one of the produce
d fragments originating from the neck which connects the other two. In spit
e of the large energy dissipation, structure effects in the charge partitio
n seem to affect part of events.