  We propose a collinear factorization formula for the associated production of
one particle and a Drell-Yan pair in hadronic collisions. It is shown that
additional collinear singularities appearing in the next-to-leading order
calculations that can not be factorized into parton and fragmentation functions
are systematically renormalized by introducing fracture functions.
Next-to-leading order coefficient functions for cross-sections double
differential in the fractional energy of the identified hadron and lepton pair
invariant mass are presented.
