  In the asymptotic limit $Q^2 \gg m^2$, the heavy flavor Wilson coefficients
for deep--inelastic scattering factorize into the massless Wilson coefficients
and the universal heavy flavor operator matrix elements resulting from
light--cone expansion. In this way, one can calculate all but the power
corrections in $(m^2/Q^2)^k, k > 0$. The heavy flavor operator matrix elements
are known to ${\sf NLO}$. We present the last 2--loop result missing in the
unpolarized case for the renormalization at 3--loops and first 3--loop results
for terms proportional to the color factor $T_F^2$ in Mellin--space. In this
calculation, the corresponding parts of the ${\sf NNLO}$ anomalous dimensions
\cite{LARIN,MVVandim} are obtained as well.
