  An algorithm for calculating two-loop propagator type Feynman diagrams with
arbitrary masses and external momentum is proposed. Recurrence relations
allowing to express any scalar integral in terms of basic integrals are given.
A minimal set consisting of 15 essentially two-loop and 15 products of one-loop
basic integrals is found. Tensor integrals and integrals with irreducible
numerators are represented as a combination of scalar ones with a higher
space-time dimension which are reduced to the basic set by using the
generalized recurrence relations proposed in Ref.[1] (Phys.Rev.D54 (1996)
6479).
