The effects of wetting hysteresis on the properties and behaviour of pendular liquid bridges between spherical particles have been investigated both experimentally and theoretically. A thermodynamic analysis shows the existence of metastable states that would account for the observed pinning of the three-phase contact line. The most important findings, with respect to the role of capillary interactions in agglomeration processes, are that (a) some of the kinetic energy of "wet" agglomerates may be dissipated during collisions by such hysteresis, (b) the bridge rupture distance is increased and (c) pinning will result in a maximum in the force-separation characteristics. (C) 2003 Elsevier Science B.V All rights reserved.