A key problem in multi-agent systems research is identifying appropriate techniques to facilitate effective cooperation between agents. In this paper, we investigate the efficacy of a novel market-based aggregation technique in addressing this problem. An incremental transaction-based protocol is introduced where agents establish links by buying and selling from each other. Market transactions equate to agents coordinating their plans and sharing their resources to meet the global objective. An important contribution of this study is to clarify whether, in some circumstances, a market-based model leads to the effective formation of agent teams (or coalitions) and thus, solutions to the problem-solving task.