An energetic electron beam propagating along the field lines in the ionosphere excites electron Bernstein waves having small group velocity across the beam. Two Bernstein waves may nonlinearly couple with each other to produce electromagnetic waves at sum and difference frequencies. A kinetic theory of this process has been developed using a guiding center formalism. Employing the nonlinear coupling coefficient, an estimate of the electromagnetic emissions at cyclotron harmonics has been made. The emitted field amplitude scales directly as the product of pump wave field strengths and varies inversely with their frequency. ¿ American Geophysical Union 1990