UNIVERSAL MODULI-DEPENDENT STRING THRESHOLDS IN Z(2)XZ(2) ORBIFOLDS

In the context of a recently proposed method for computing exactly str ing loop corrections regularized in the infra-red, we determine and ca lculate the universal moduli-dependent part of the threshold correctio ns to the gauge couplings for the symmetric Z(2) x Z(2) orbifold model . We show that these corrections decrease the unification scale of the underlying effective field theory. We also comment on the relation be tween this infra-red regularization scheme and other proposed methods.