  For two-loop two-point diagrams with arbitrary masses, an algorithm to derive
the asymptotic expansion at large external momentum squared is constructed. By
using a general theorem on asymptotic expansions of Feynman diagrams, the
coefficients of the expansion are calculated analytically. For some two-loop
diagrams occurring in the Standard Model, comparison with results of numerical
integration shows that our expansion works well in the region above the highest
physical threshold.
