  In this talk we discuss an algorithm for the numerical calculation of
one-loop QCD amplitudes and present results at next-to-leading order for jet
observables in electron-positron annihilation calculated with the
above-mentioned method. The algorithm consists of subtraction terms,
approximating the soft, collinear and ultraviolet divergences of QCD one-loop
amplitudes, as well as a method to deform the integration contour for the loop
integration into the complex plane to match Feynman's i delta rule. The
algorithm is formulated at the amplitude level and does not rely on Feynman
graphs. Therefore all ingredients of the algorithm can be calculated
efficiently using recurrence relations. The application of this method to the
leading-colour contribution of e+ e- --> n jets, with n up to seven,
demonstrates the efficiency of the approach.
