  The gluon radiation induced by multiple scattering of a hard parton in
expanding quark-gluon plasma is investigated. The radiative energy loss of hard
parton jet is shown to decrease considerably when angular size of extracted jet
goes up, but the fraction of loss survives even for the reasonable wide cone of
angles due to the coherent effects taking into account the rescattering of the
radiated gluons in the QCD medium. The possible application to the jet
quenching phenomenon in heavy ion collisions at LHC energies is discussed.
