  The resonant interaction between kinetic Alfv\'{e}n and ion-acoustic waves is
considered using the Hall-MHD theory. The results of previous authors are
generalized to cover both finite Larmor radius as well as the ideal MHD
results. It is found that the three wave coupling is strongest when the
wavelength is comparable to the ion-sound gyroradius. Applications of our work
to weak turbulence theories as well as to the heating of the solar corona are
pointed out.
