Rigidity of Kleinian groups

Discrete subgroups of PSL(2,C) are called Kleinian groups. The famous Mostow rigidity theorem says that Kleinian groups of finite co-volume (=lattices) do not admit any faithful discrete representation into PSL(2,C) except for conjugations. I will present a new rigidity theorem for finitely generated Kleinian groups which are not necessarily lattices, and explain how this compares with Sullivan's rigidity theorem.