  We study within the light-cone path integral approach the induced gluon
emission from a fast quark passing through a finite-size QCD plasma. We show
that the leading log approximation used in previous studies fails when the
gluon formation length becomes of the order of the length of the medium
traversed by the quark. Calculation of the energy loss beyond the leading log
approximation gives the energy loss which grows logarithmically with quark
energy contrary to the energy independent prediction of the leading log
approximation.
