A factorization of regular generalized Nevanlinna functions

LetQ be a regular operator valued generalized Nevanlinna function with negative index , i.e. . It is shown that then there exists a rational functionB(z), which collects the generalized poles and zeros ofQ that are not of positive type such that the function belongs to the Nevanlinna class .The author acknowledges support of the Fonds zur Förderung der wissenschaftlichen Forschung of Austria, Project P 12176 MAT, and of the EU Research Training Network, Contract No. HPRN-CT-2000-00116.