A 3-D mathematical model is developed for fields due to currents in the presence of a planarly stratified composite medium. General expressions for the dyadic Green's functions in the case of a non-magnetic, electrically uniaxial type of anisotropy are derived herein as a necessary first step. The associated electric-electric dyadic Green's function is constructed from transverse electric and transverse magnetic scalar modes using interface and radiation (at infinity) conditions. The regular part of the electric-electric dyadic Green's function is computed by a Fast Fourier Transform technique and is used to calculate the electromagnetic response of a planarly composite material having a delamination of various thickness at a given interface.