The transportation planning of oil products in Brazil's multimodal network is a complex problem that involves several negotiations between decentralized entities in order to agree onthe products to transfer, their amounts,and allocation of shared resources. Due to such complexity,adecision supporting tools that can help the decisionmakers is a clear need. This paper presents a model to solve such problem based on a new multi-agent auction protocol and emphasizes the conception of bids asa mannerto generate better commitments for all involvedentities.The developed modelis used to solvea real scenario of the Brazilian oil supply chain.