MODULI SPACE OF CHAUDHURI-HOCKNEY-LYKKEN STRINGS

We discuss an orbifold of the toroidally compactified heterotic string which gives a global reduction of the dimension of the moduli space w hile preserving the supersymmetry. This construction yields the moduli space of the first of a series of reduced rank theories with maximal supersymmetry discovered recently by Chaudhuri, Hockney, and Lykken. S uch moduli spaces contain nonsimply laced enhanced symmetry points in any spacetime dimension D<10. Precisely in D=4 the set of allowed gaug e groups is invariant under electric-magnetic duality, providing furth er evidence for the S duality of the D=4 heterotic string.