We study the dimensional reduction of a ten-dimensional supersymmetric E_8
gauge theory over six-dimensional coset spaces. We find that the coset space
dimensional reduction over a symmetric coset space leaves the four dimensional
gauge theory without any track of the original supersymmetry. On the contrary
the dimensional reduction over a non symmetric coset space leads to a softly
broken supersymmetric gauge theory in four dimensions. The SO_7/SO_6 and
G_2/SU(3) are used as representative prototypes of symmetric and non symmetric
coset spaces respectively.Comment: latex, 13 pages, version to be published in Phys. Lett.