  We present a model in which the same modulus field breaks both SUSY and a
simple GUT gauge group down to the SM gauge group. The modulus is stabilized by
the inverted hierarchy mechanism in a perturbative region so that the model is
calculable. This is the first example of this kind in the literature. All mass
scales (other than the Planck scale) are generated dynamically. In one of the
models doublet-triplet splitting is achieved naturally by the sliding singlet
mechanism while another model requires fine tuning. The gauge mediation
contribution to the right handed slepton (mass)$^2$ is negative. But, for the
modulus vacuum expectation value close to the GUT scale, the supergravity
contribution to the slepton (mass)$^2$ is comparable to the gauge mediation
contribution and thus a realistic spectrum can be attained.
