  We show that it is possible to introduce the confining hidden sector gauge
group SU(5)' with the chiral matter 10 plus 5-bar, which are neutral under the
standard model gauge group, toward a gauge mediated supersymmetry breaking
(GMSB) in a Z_{12-I} orbifold compactification of E_8xE_8 heterotic string.
Three families of MSSM result without exotics. We also find a desirable matter
parity P (or R-parity) assignment. We note that this model contains the
spectrum of the Lee-Weinberg model which has a nice solution of the mu problem.
