  We describe a general method that enables us to obtain all the singular terms
of helicity amplitudes of n-parton processes at one loop. The algorithm uses
helicity amplitudes at tree level and simple color algebra.
  We illustrate the method by calculating the singular part of the one loop
helicity amplitudes of all $ 2\to 3$ parton subprocesses. The results are used
to derive the soft gluon limit of the cross sections of all $2\to 4$ parton
scattering subprocesses which provide a useful initial condition for the
angular ordering approximation to coherent multiple soft gluon emission,
incorporated in existing Monte Carlo simulation programs.
