  Assuming the existence of a supersymmetric U(1) gauge factor at the TeV
energy scale (motivated either by the superstring-inspired E_6 model or
low-energy electroweak phenomenology), several important consequences are
presented. The two-doublet Higgs structure at the 100 GeV energy scale is shown
to be different from that of the Minimal Supersymmetric Standard Model (MSSM).
A new neutral gauge boson Z' corresponding to the extra U(1) mixes with the Z.
The supersymmetric scalar quarks and leptons receive new contributions to their
masses from the spontaneous breaking of this extra U(1). The assumption of
universal soft supersymmetry breaking terms at the grand-unification energy
scale implies a connection between the U(1) breaking scale and the ratio of the
vacuum expectation values of the two electroweak Higgs doublets.
