A general reduction method for one-loop N-point integrals

In order to calculate cross sections with a large number of particles/jets in the final state at next-to-leading order, one has to reduce the occurrin g scalar and tensor one-loop integrals to a small set of known integrals. I n massless theories, this reduction procedure is complicated by the presenc e of infrared divergences. Working in n = 4 - 2 epsilon dimensions, it will be outlined how to achieve such a reduction for diagrams with an arbitrary number of external legs. As a result, any integral with more than four pro pagators and generic 4-dimensional external momenta can be reduced to box i ntegrals.