A factorization of regular generalized Nevanlinna functions

Let Q be a regular operator valued generalized Nevanlinna function with negative index (kappa), i.e. Q (element of) N(kappa)(H). It is shown that then there exists a rational function B(z), which collects the generalized poles and zeros of Q that are not of positive type such that the function B(z)*Q(z)B(z) belongs to the Nevanlinna class N0(H).