  Given a link map f into a manifold of the form Q = N \times \Bbb R, when can
it be deformed to an unlinked position (in some sense, e.g. where its
components map to disjoint \Bbb R-levels) ? Using the language of normal
bordism theory as well as the path space approach of Hatcher and Quinn we
define obstructions \widetilde\omega_\epsilon (f), \epsilon = + or \epsilon =
-, which often answer this question completely and which, in addition, turn out
to distinguish a great number of different link homotopy classes. In certain
cases they even allow a complete link homotopy classification.
  Our development parallels recent advances in Nielsen coincidence theory and
leads also to the notion of Nielsen numbers of link maps.
  In the special case when N is a product of spheres sample calculations are
carried out. They involve the homotopy theory of spheres and, in particular,
James--Hopf--invariants.
