The matrix-form integral encounter theory (IET) is generalized to consider bulk reversible association–dissociation reactions. The many-particle derivation of the IET kinetic equations is based on the extension of the formalism of “effective” particles developed earlier. As a result, an infinite hierarchy for vector correlation patterns is obtained and truncated in the way suggested earlier for elementary reactions. We believe that such an extension of the IET is utterly important for the kinetic description of a great number of diffusion-influenced chemical reactions.