  We present a new approach for generating solutions in heterotic string theory
compactified down to three dimensions on a torus with d+n>2, where d and n
stand for the number of compactified space--time dimensions and Abelian gauge
fields, respectively. It is shown that in the case when d=2k+1 and n is
arbitrary, one can apply a solution--generating procedure starting from
solutions of the stationary Einstein theory with k Maxwell fields; our approach
leads to classes of solutions which are invariant with respect to the total
group of three-dimensional charging symmetries. We consider a particular
extension of the stationary Einstein--multi-Maxwell theory obtained on the
basis of the Kerr--multi-Newman--NUT special class of solutions and establish
the conditions under which the resulting multi--dimensional metric is free of
Dirac string peculiarities.
