  We present a supersymmetric extension of the Standard Model (USSM-A) with an
anomalous U(1) and Stueckelberg axions for anomaly cancellation, generalizing
similar non-supersymmetric constructions. The model, built by a bottom-up
approach, is expected to capture the low-energy supersymmetric description of
axionic symmetries in theories with gauged anomalous abelian interactions,
previously explored in the non-supersymmetric case for scenarios with
intersecting branes. The choice of a USSM-like superpotential, with one extra
singlet superfield and an extra abelian symmetry, allows a physical axion-like
particle in the spectrum. We describe some general features of this
construction and in particular the modification of the dark-matter sector which
involves both the axion and several neutralinos with an axino component. The
axion is expected to be very light in the absence of phases in the
superpotential but could acquire a mass which can also be in the few GeV range
or larger. In particular, the gauging of the anomalous symmetry allows
independent mass/coupling interaction to the gauge fields of this particle, a
feature which is absent in traditional (invisible) axion models. We comment on
the general implications of our study for the signature of moduli from string
theory due to the presence of these anomalous symmetries.
