  We study high mass dilepton production from gluon-induced processes, $g q \to
q \gamma^*$, $g \bar q \to \bar q \gamma^*$, and $g g \to q \bar q \gamma^*$,
in a thermally equilibrated but chemically under-saturated partonic matter that
is expected to be created in the initial stage of ultra-relativistic heavy ion
collisions. Regulating the divergence in these processes by the thermal quark
mass, we find that gluon-induced processes are more important than the
leading-order $q\bar q$ annihilation process as a result of the larger number
of gluons than quarks in the partonic matter. The dependence of the thermal
dilepton yield from the partonic stage of heavy ion collisions on the initial
conditions for the partonic matter is also studied. We further discuss the
feasibility of observing thermal dileptons from the quark-gluon plasma in heavy
ion experiments.
