  We explain the observation of clusters in the tunneling resonance spectra of
small metallic particles of few nanometer size. Each cluster of resonances is
identified with one excited single--electron state of the metal particle,
shifted as a result of the different nonequilibrium occupancy configurations of
the other single--electron states. Assuming the underlying classical dynamics
of the electrons to be chaotic, we determine the typical shift to be $\Delta/g$
where $g$ is the dimensionless conductance of the grain.
