We study the determinants of market structure in financial intermediation markets when property rights over information are weak. We show that incentives to gather information to screen firms can be preserved in decentralized markets with more than one intermediary. In equilibrium, each intermediary possesses local monopoly power, which is preserved by implicit contracts between intermediaries. These, in turn, impose constraints on aggregate market structure. We examine the robustness of such self-enforcing behavior to entry and present a theory in which market structure is endogenously determined.