  The ``preon-trinity'' model for the compositeness of leptons, quarks and
heavy vector bosons predicts several new heavy leptons and quarks. Three of
them can be produced in $e^{+}e^{-}$ annihilations at CERN LEP energies, since
they can be created out of a system of three preons and their antipreons, where
three preons form a heavy lepton or quark, while the other three go into a
normal lepton or quark. In fact, these new particles are predicted to be
lighter than the top quark, while the top itself cannot be produced this way,
due to its particular preon substructure. The empirical situation is analyzed,
and the most likely masses are estimated.
