  The contribution of radiative processes to $p_\perp$-broadening of fast
partons in a quark-gluon plasma is investigated. Calculations are performed
beyond the soft gluon approximation. It is shown that the radiative correction
to $\langle p_{\perp}^2\rangle$ for conditions of heavy ion collisions at RHIC
and LHC is negative and can be comparable in absolute value with the
nonradiative contribution. This prediction differs radically from the
essentially positive contribution of radiative processes to
$p_{\perp}$-broadening, which was predicted earlier in the literature.
