We have investigated the excitation of tearing instabilities driven by lower hybrid waves in the current sheet. Considering a two-dimensional equilibrium, we have shown that lower hybrid waves observed throughout the plasma sheet can cause large anomalous resistivity as a consequence of nonlinear interactions and significantly influence the excitation of tearing mode in the layer, where Bx(z) reverses sign. We have found that the perturbed ponderomotive force gives two new physical effects, one due to current gradients in the inner core of the current sheet (z≪Δ≪&lgr;, where &lgr; is the current sheet width and Δ is the thickness of the field reversal layer) and the other due to anomalous resistivity in the outer core (Δ≪z≤&lgr;). In the presence of these effects, we have demonstrated that global tearing modes with growth times ranging from fraction of a second to several tens of milliseconds are excited for wave electric fields of order of a few mV/m and scale lengths in the range k0yLz1, where k0y is the wavenumber of the lower hybrid waves and Lz is the perturbation scale length. Finally, we have discussed the relevance of this wave-driven mode to the magnetic reconnection and the substorm onset processes. ¿ American Geophysical Union 1996