  We present approximations to tree level multiparton scattering amplitudes
which are appropriate when two partons are unresolved. These approximations are
required for the analytic isolation of infrared singularities of n+2 parton
scattering processes contributing to the next-to-next-to-leading order
corrections to n jet cross sections. In each case the colour ordered matrix
elements factorise and yield a function containing the singular factors
multiplying the n parton amplitudes. When the unresolved particles are not
colour connected, the approximations are simple products of the familar eikonal
and Altarelli-Parisi splitting functions used to describe single unresolved
emission. However, when the unresolved particles are colour connected the
factorisation is more complicated and we introduce new and general functions to
describe the triple collinear and soft/collinear limits in addition to the
known double soft gluon limits of Berends and Giele. As expected the triple
collinear splitting functions obey an N=1 SUSY identity. To illustrate the use
of these double unresolved approximations, we have examined the singular limits
of the tree level matrix elements for e+e- to 5 partons when only three partons
are resolved. When integrated over the unresolved regions of phase space, these
expressions will be of use in evaluating the O(alpha_s^3) corrections to the
three jet rate in electron positron annihilation.
