The plasmon hybridization method is generalized to calculate the plasmon modes and optical properties of solid and dielectric-core/metallic-shell particles of geometrical structures that can be described using separable curvilinear coordinates. The authors present a detailed discussion of the plasmonic properties of hollow metallic nanowires with dielectric cores and core/shell structures of oblate and prolate spheroidal shapes. They show that the plasmon frequencies of these particles can be expressed in a common form and that the plasmon modes of the core/shell structures can be viewed as resulting from the hybridization of the solid particle plasmons associated with the outer surface of the shell and of the cavity plasmons associated with the inner surface.