  The QED processes e^+ e^- -> e^+ e^- \mu^+ \mu^- and e^+ e^- -> e^+ e^-
\tau^+ \tau^- are studied with the L3 detector at LEP using an untagged data
sample collected at centre-of-mass energies
  161 GeV < sqrt{s} < 209 GeV. The tau-pairs are observed through the
associated decay of one tau into e\nu\nu and the other into \pi\pi\nu . The
cross sections are measured as a function of sqrt{s}. For muon pairs, the cross
section of the \gamma\gamma -> \mu^+\mu^- process is also measured as a
function of the two-photon centre-of-mass energy for 3 GeV < W_{\gamma\gamma} <
40 GeV. Good agreement is found between these measurements and the O(\alpha^4)
QED expectations. In addition, limits on the anomalous magnetic and electric
dipole moments of the tau lepton are extracted.
