We examine liquid-liquid-particle ternary blends composed of two immiscible polymers and spherical silica particles across a wide range of compositions. The particles are fully wetted by one of the liquids. Rheological behavior is investigated through continuous shear flow and small/large amplitude oscillatory shear experiments. We observe various percolating structures of the particles bound by capillary interactions, as well as particles-in-drops or drops-in-suspension microstructures. These morphological changes with composition induce significant alteration in a linear viscoelastic response and yielding of the three-phase system. Similarly to the observations in wet granular materials, both the elastic plateau modulus and the yield stress of our ternary system exhibit a maximum as the wetting phase content increases for a fixed particle concentration. We show that this phenomenon is linked to an evolution of the structure from a meniscus-bridged particle network to a selectively filled bicontinuous state and eventually to a drops-in-suspension microstructure upon phase inversion. Remarkably, the presence of particles enables the formation of bicontinuous structures over a wide region of the compositional space, while no such structures could be produced for the particle-free immiscible polymer blend. This phenomenon results from selective partitioning of the particles in the wetting phase domain, which imparts a solidlike behavior of the latter due to particle crowding. Therefore, the formation of strong physical gels plays a central role in both the structure stabilization and the route to phase inversion for such ternary systems. (C) 2017 The Society of Rheology.