We formulate and discuss a reduction theorem for Poisson pencils associated
with a class of integrable systems, defined on bi-Hamiltonian manifolds,
recently studied by Gel'fand and Zakharevich. The reduction procedure is
suggested by the bi-Hamiltonian approach to the Separation of Variables
problem.Comment: Latex, 14 pages. Proceeding of the Conference "Multi-Hamiltonian
Structures: Geometric and Algebraic Aspects". August 9-18, 2001 Bedlewo,
Poland. To appear in ROM