  Recently it was conjectured by Gibbons and Townsend that the large n limit of
an N=4 superconformal extension of the n-particle Calogero model might provide
a microscopic description of the extreme Reissner-Nordstrom black hole near the
horizon. In this paper a possibility to construct an SU(1,1|2) invariant
extension of the Calogero model is considered. We treat in detail the
two-particle case and comment on some peculiarities intrinsic to n>2
generalizations.
