We derive the duality symmetries relevant to moduli dependent gauge co
upling constant threshold corrections, in Coxeter Z(N) orbifolds. We c
onsider those orbifolds for which the point group leaves fixed a two-d
imensional sublattice Lambda(2), of the six-dimensional torus lattice
Lambda 6, where Lambda(6) cannot be decomposed as Lambda(2) circle plu
s Lambda 4.