C-algebraic deformations of homogeneous spaces G/Gamma are constructe
d by completing dense subspaces of C-0(G/Gamma) in a different multipl
ication and C-norm; these deformations are equivariant in the sense t
hat they still carry a natural action of G by left translation. The mo
tivating examples are the noncommutative Heisenberg manifolds of Rieff
el, but the construction given here is based on the authors' twisted d
ual-group algebras, which are equivariant deformations of C-0(G). The
procedure is general enough to give other recently studied families of
noncommutative spaces and some interesting new examples of simple C-
algebras. (C) 1997 Academic Press.