  The understanding of the particle spectra resulting from acceleration in
relativistic shocks as they occur in extragalactic sources, is essential for
the interpretation of the cosmic ray spectrum above the ankle ($E_p>3\cdot
10^{18}$ eV). It is believed that extragalactic sources like Active Galactic
Nuclei and Gamma Ray Bursts can produce particle spectra up to $E_p\sim
10^{21}$ eV. In this contribution, subluminal shocks are investigated with
respect to different shock boost factors $\Gamma$ and the inclination angle
between the shock normal and the magnetic field $\psi$. A correlation between
the boost factor and the spectral behavior of the emitted particles is found.
The results are compared to Active Galactic Nuclei and Gamma Ray Burst diffuse
cosmic ray contribution and the observed cosmic ray spectrum at the highest
energies.
