  We construct three quasi-supersymmetric $G^3$ GUT models with $S_3$ symmetry
and gauge coupling unification from intersecting D6-branes on Type IIA
orientifolds. The Standard Model fermions and Higgs doublets can be embedded
into the bifundamental representations in these models, and there is no any
other unnecessary massless representation. Especially in Model I with gauge
group $U(4)^3$, we just have three-family SM fermions and three pairs of Higgs
particles. The $G^3$ gauge symmetry in these models can be broken down to the
Standard Model gauge symmetry by introducing light open string states. And 1
TeV scale supersymmetry breaking soft masses imply the reasonable intermediate
string scale.
