  Within the context of the extended bi-spinor gauge theory we describe a new
off-shell realization of scalar supersymmetry (s-susy) of massless interacting
fields with U(1), U(1) x SU(N) and U(1) x SU(N_1) x SU(N_2) gauge groups.
S-susy acts in the space of graded differential forms. The realization is
non-linear in the non-abelian case. S-susy would not require the doubling of
the SM particle spectrum. Instead, essentially only the forth generation of
quarks and leptons would be needed as extra field content. The theory is by
construction globally U(2,2) invariant and is an example of a supersymmetric
CFT.
