  We study the correlator of concentric circular Wilson loops for arbitrary
radii, spatial and internal space separations. For real values of the
parameters specifying the dual string configuration, a typical Gross-Ooguri
phase transition is observed. In addition, we explore some analytic
continuation of a parameter $\gamma$ that characterizes the internal space
separation. This enables a ladder limit in which ladder resummation and string
theory computations precisely agree in the strong coupling limit. Finally, we
find a critical value of $\gamma$ for which the correlator is supersymmetric
and ladder diagrams can be exactly resummed for any value of the coupling
constant.
