  In this paper we derive part of the low energy action corresponding to
F-theory compactifications on specific eight manifolds with SU(3) structure.
The setup we use can actually be reduced to compactification of six-dimensional
supergravity coupled to tensor multiplets on a T^2 with duality twists. The
resulting theory is a N=2 gauged supergravity coupled to vector-tensor
multiplets.
