We propose to develop a framework for agent-based electronic markets (e-markets) for project supply chain coordination, where subcontractors interact and transact with other subcontractors within supply-chain networks with the assistance of software agents. The e-markets for project supply chain coordination complements our agent-based project schedule coordination framework by applying the advanced transaction techniques developed for electronic commerce systems. According to external changes, subcontractors trade not only their timing with other subcontractors through multi-agent negotiation, but also their tasks with the same specialty contractors, which may be in better positions to execute the tasks, through e-markets. The multi-agent decision-support system wilt help subcontractors explore various new choices and opportunities that the e-markets offer. The business-to-business e-markets support the current project coordination trends in which subcontracting or outsourcing now prevails.