  The Standard Model for electroweak interactions derives four vector gauge
boson from an SU(2)xU(1) symmetry. A doublet of complex scalar (Higgs) bosons
is added to generate masses by spontaneous symmetry breaking. Both, the four
vector bosons and four scalar bosons corresponding to the Higgs bosons of the
Standard Model are shown to emerge as gauge bosons from an underlying SU(3)
symmetry of electroweak lepton interactions. For the known leptons, the latter
symmetry implies purely axial coupling of the Z boson to charged leptons, if
the photon is required to have purely vector coupling. The corresponding
Weinberg angle is determined by sin{\theta} = 1/2. The same SU(3) symmetry
holds for quarks as well, if the observed fractional electric quark charges are
averages of integer charges, according to the Han-Nambu scheme.
