  We discuss the QCD sum rule calculation of the heavy-quark effective theory
parameters, $\lambda_E$ and $\lambda_H$, which correspond to matrix elements
representing quark-gluon three-body components in the $B$-meson wavefunction.
We derive the sum rules for $\lambda_{E,H}$ calculating the new higher-order
QCD corrections, i.e., the order $\alpha_s$ radiative corrections to the Wilson
coefficients associated with the dimension-5 quark-gluon mixed condensates, and
the power corrections due to the dimension-6 vacuum condensates. We find that
the new radiative corrections significantly improve the stability of the
corresponding Borel sum rules and lead to the reduction of the values of
$\lambda_{E,H}$. We also discuss the renormalization-group improvement for the
sum rules and present update on the values of $\lambda_{E,H}$.
