  We construct an explicit scheme to associate to any potential symbol an
operator acting between sections of natural bundles (associated to irreducible
representations) for a so-called AHS-structure. Outside of a finite set of
critical (or resonant) weights, this procedure gives rise to a quantization,
which is intrinsic to this geometric structure. In particular, this provides
projectively and conformally equivariant quantizations for arbitrary symbols on
general (curved) projective and conformal structures.
