  We report a measurement of the process gamma gamma* --> pi0 with a 759
fb^{-1} data sample recorded with the Belle detector at the KEKB
asymmetric-energy e+e- collider. The pion transition form factor, F(Q^2), is
measured for the kinematical region 4 GeV^2 <~ Q^2 <~ 40 GeV^2, where -Q^2 is
the invariant mass squared of a virtual photon. The measured values of
Q^2|F(Q^2)| agree well with the previous measurements below Q^2 ~= 9 GeV^2 but
do not exhibit the rapid growth in the higher Q^2 region seen in another recent
measurement, which exceeds the asymptotic QCD expectation by as much as 50%.
