We consider complete
intersections V in Cm which have an isolated singularity at 0. When V admits
a C∗ action, one has the orbit space V∗= V −{0}∕C∗. In this paper we
determine when V∗ is a topological manifold, or in some cases, the precise
dimension of the set Σ along which V∗ is not a manifold. For proper actions we
consider a naturaI complex structure on the space V∗ and determine some
equivalences among V∗ for different V . Our methods are topological; the results are
expressed numerically in terms of weighted degrees of the polynomials defining
V .