  We use a nonpertubative approach which combines coupled channel Lippmann
Schwinger equations with meson-meson potentials provided by the lowest order
chiral Lagrangian. By means of one parameter, a cut off in the momentum of the
loop integrals, which results of the order of 1 GeV, we obtain singularities in
the S-wave amplitudes corresponding to the $\sigma$, f_0 and a_0 resonances.
The $\pi \pi \to \pi \pi, \pi \pi \to K \bar{K}$ phase shifts and
inelasticities in the T = 0 scalar channel are well reproduced as well as the
$\pi^0 \eta$ and $K \bar{K}$ mass distributions in the T = 1 channel.
Furthermore, the total and partial decay widths of the f_0 and a_0 resonances
are properly reproduced including also the decay into the $\gamma \gamma$
channel. The results seem to indicate that chiral symmetry constraints at low
energy and unitarity in coupled channels is the basic information contained in
the meson-meson interaction below $\sqrt{s} \simeq 1.2 GeV$.
