  We propose an extension of the Standard Model inspired by the E_8 x E_8
Heterotic String. In order that a reasonable effective Lagrangian is presented
we neglect everything else other than the ten-dimensional N=1 supersymmetric
Yang-Mills sector associated with one of the gauge factors and certain
couplings necessary for anomaly cancellation. We consider a compactified
space-time M_4 x B_0/Z_3, where B_0 is the nearly Kaehler manifold SU(3)/U(1) x
U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce
dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism
leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a
N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian
and demonstrate that an extension of the Standard Model is obtained with
interesting features including a conserved baryon number and fixed tree level
Yukawa couplings and scalar potential. The spectrum contains new states such as
right handed neutrinos and heavy vector-like quarks.
