A new algorithm is proposed to compute magnetotelluric (MT) curves for a horizontally layered earth with laterally inhomogeneous conductivity. It is fast and ensures correction of induced eddy currents and galvanic distortions of MT curves produced by 3D inhomogeneities. The computation time is short (similar to 1 min) due to the use of the perturbation method for solving Maxwell's equations. The suggested algorithm has a better performance than the more costly classical Trefftz method but has an applicability limitation.
