  We present a new mechanism to explain naturally and through a common flavour
symmetry the mildly hierarchical neutrino masses with large mixings and the
hierarchical Yukawa matrices with small mixing angles. Although this mechanism
is not linked to a particular flavour symmertry, it is particularly simple in
the framework of a SU(3) flavour symmetry. In this model, we obtain exactly
maximal atmospheric mixing, large although not maximal solar mixing and a
normal neutrino hierarchy. All neutrino parameters are basically fixed. For
instance, we predict that the angle $\theta_{13}$ comes entirely from the
charged lepton sector and, using the difference of the solar angle from
maximality, we can fix the mass of lightest neutrino.
