NONLINEAR LOCAL SUPERSYMMETRIC SU(5)-MODEL

We construct a realistic nonlinear supersymmetric SU(5) model without superpartner particles in curved space and investigate the Higgs secto r in the limit of flat space. We need at least an adjoint-, a quintupl et- and an antiquintuplet-Higgs multiplet. In order to obtain a realis tic breakdown of SU(5) to SU(3) x U(1) at tree level we have to modify the vacuum structure of the adjoint representation in comparison to o ther SU(5)-models. This model requires an ''elegant'' fine-tuning. We determine the mass spectrum of the electroweak Higgs sector.