  We identify a natural analytic continuation in four dimensions from Minkowski
signature to a signature with two time-like momentum components. For two, three
and four-point diagrams at fixed external momenta, this continuation can be
implemented as a countour deformation that leaves dependence on the momenta
unchanged. For arbitrary ultraviolet-finite scalar diagrams it is possible to
do two integrals per loop in terms of simple poles in the new signature. This
results in a representation of any such diagram as a sum of terms, each with
two remaining integrals per loop.
