  We calculate moments of the $O(\alpha_s^3)$ heavy flavor contributions to the
  Wilson coefficients of the structure function $F_2(x,Q^2)$ in the region
  $Q^2\gg m^2$. The massive Wilson coefficients are obtained as convolutions of
massive operator matrix elements (OMEs) and the known light flavor Wilson
coefficients. The calculation of moments of the massive OMEs involves a first
independent recalculation of moments of the fermionic contributions to all
3--loop anomalous dimensions of the unpolarized twist--2 local composite
operators stemming from the light--cone expansion. The expressions for the
massive OMEs are now known for general values of the Mellin variable $N$ apart
of one coefficient in the constant term, for which only a series of moments is
computed.
