Collective behaviour of a crown ether channel, bis[(benzo-15-crown-5)-15-yl methyl] pimelate, in a planar lipid bilayer membrane has been studied through electrophysiological methods. A characteristic feature of these channels is their sequential opening, indicated by a uniform stepwise increase in the multi-channel current. The experimental results show that there are three modes of relaxation, of which the slowest one is attributed to the channel-channel interaction. The latter varies with the number of channels incorporated in the bilayer membrane, leading to the interpretation that crown channels behave cooperatively.