This study constructs a successive Cournot model to investigate the possibility that a separated upstream input supplier can solely sell the intermediate good to a separated downstream manufacturer through an exclusive contract in the presence of a vertically integrated rival. We find that the separated firms are indifferent on whether to sign the exclusive contract or not if the downstream party is less efficient than the integrated firm in producing the final good. Next, the separated firms with an efficient downstream party are indifferent between signing or not signing, willing to sign, and not willing to sign the exclusive contract if the upstream cost differential is relatively low, medium, and high, respectively. Finally, signing such an exclusive contract does not increase consumer surplus and social welfareEste trabajo construye un modelo sucesivo de Cournot para investigar que un proveedor de insumos realice ventas exclusivas a un productor en presencia de un competidor verticalmente integrado. Se encuentra que las empresas se encontrarán indiferentes en tener un contrato de exclusividad si el productor es menos eficiente en la producción del bien que la firma integrada. Asimismo, la firma de un contrato de exclusividad dependerá del diferencial de costos del proveedor del insumo. Finalmente, un contrato de exclusividad no aumenta el excedente del consumidor o el bienestar social.