  It is shown that a very simple multiplicative random complex matrix model
generalizes the large-N phase structure found in the unitary case: A
perturbative regime is joined to a non-perturbative regime at a point where the
smoothness of some quantities breaks down. A generic complex Wilson loop matrix
in a field theory admitting a 't Hooft planar limit could display a phase
transition in that limit as nonlinear effects become dominating over linear
ones.
