  Making use of toric geometry we construct a class of global F-theory GUT
models. The base manifolds are blowups of Fano threefolds and the Calabi-Yau
fourfold is a complete intersection of two hypersurfaces. We identify possible
GUT divisors and construct SO(10) models on them using the spectral cover
construction. We use a split spectral cover to generate chiral matter on the 10
curves in order to get more degrees of freedom in phenomenology. We use abelian
flux to break SO(10) to SU(5)\times U(1) which is interpreted as a flipped
SU(5) model. With the GUT Higgses in the SU(5)\times U(1) model it is possible
to further break the gauge symmetry to the Standard Model. We present several
phenomenologically attractive examples in detail.
