Using superspace techniques we construct the general theory describing D=4,
N=2 supergravity coupled to an arbitrary number of vector and scalar--tensor
multiplets. The scalar manifold of the theory is the direct product of a
special Kaehler and a reduction of a Quaternionic-Kaehler manifold. We perform
the electric gauging of a subgroup of the isometries of such manifold as well
as ``magnetic'' deformations of the theory discussing the consistency
conditions arising in this process. The resulting scalar potential is the sum
of a symplectic invariant part (which in some instances can be recast into the
standard form of the gauged N =2 theory) and of a non--invariant part, both
giving new deformations. We also show the relation of such theories to flux
ompactifications of type II string theories.Comment: LaTeX, 26 pages. v2 Improved discussion in sect. 4 and references
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