  The measurement of the trilinear couplings A in the part of the Lagrangian
which breaks supersymmetry softly will be a difficult experimental task. In
this report the heavy Higgs decays H,A -> stau_1 stau_2 to stau pairs are
investigated for measuring the stau trilinear coupling A_tau. Based on detailed
simulations of signal and backgrounds for a specific reference point in future
high luminosity e+e- linear collider experiments, it is concluded that the
parameter $_tau can be determined with a precision at the 10% level in the
region of moderate to large tan(beta).
