  Given an orientable weakly self-dual manifold X of rank two, we build a
geometric realization of the Lie algebra sl(6,C) as a naturally defined algebra
L of endomorphisms of the space of differential forms of X. We provide an
explicit description of Serre generators in terms of natural generators of L.
This construction gives a bundle on X which is related to the search for a
natural Gauge theory on X. We consider this paper as a first step in the study
of a rich and interesting algebraic structure.
