  We have analysed the Ioffe-time distribution of quarks in virtual photons
using Operator Product Expansion of the correlation function that determines
the matrix element of the corresponding quark string operator. The distribution
for a transversally polarised photon admits a spectral representation which can
be continued to the on-shell region $p^2 =0$. The resulting model Ioffe-time
distribution turns out to be larger than parametrisations of the available
$F_2^{\gamma}$ data. This result is linked to the slope of the quark
distribution at the origin, which comes out too large as well.
