  The ten--parametric internal symmetry group is found in the $D=4$
Einstein--Maxwell--Dilaton--Axion theory restricted to space--times admitting a
Killing vector field. The group includes dilaton--axion $SL(2,R)$ duality and
Harrison--type transformations which are similar to some target--space duality
boosts, but act on a different set of variables. New symmetry is used to derive
a seven--parametric family of rotating dilaton--axion Taub--NUT dyons.
