  The idea to have Higgs doublets as pseudo Nambu-Goldstone (PsNG) multiplet is
examined in the framework of supersymmetric E_6 unified theory. We show that
extra PsNG multiplets other than the expected Higgs doublets necessarily appear
in the E_6 case. If we demand that the extra PsNG multiplets neither disturb
the gauge coupling unification nor make the color gauge coupling diverge before
unification occurs, only possibility for the extra PsNG is 10+\bar{10} of
SU(5). This is realized when the symmetry breaking E_6 \to SO(10) occurs in the
\phi(27)+\phi(\bar{27}) sector while E_6 \to SU(4)_C\times SU(2)_L\times
U(1)\times U(1) in the \Sigma(78) sector. The existence of 10+\bar{10}
multiplets with mass around 1 TeV is therefore a prediction of this E_6 PsNG
scenario. Implication of their existence on the proton decay is also discussed.
