  A complex filling of a CR manifold is said to be equivariant with respect to
a CR action if the action extends to a smooth action by biholomorphisms on the
whole filling. Under a noncompactness condition for the action, we describe all
equivariant fillings of strongly pseudoconvex CR manifolds of dimension 3.
Since the standard sphere is the only compact strongly pseudoconvex CR manifold
whose automorphism group is not compact, we only have to study its fillings.
