In this report diffractive high energy reactions are discussed in a functional integral approach where hadronic amplitudes are calculated from vacuum expectation values of lightlike Wegner-Wilson loops. In the first part we calculate elastic differential cross sections for high energy and small momentum transfer elastic proton-proton (pp) scattering which are in reasonable agreement with the experimental data. In the second part we consider exclusive π^0 production in ep-scattering. At high

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... gies photon and odderon exchange contribute to this reaction. We show that odderon exchange leads to a much larger inelastic than elastic π^0 production cross section, dominating the γ contribution by orders of magnitude. Observing our process at HERA would establish the soft odderon.