Among inter-firm trade patterns, the cooperative trade system has proved to be superior to arms-length or market-oriented trade in the long run. Within the cooperative trade system, the transition from dedicated (single supplier) trade to network trade is proving a remarkable phenomenon. In our theoretical model, we compare the relative economic efficiencies between dedicated and network trade systems. Then in empirical analysis, we examine the relationship between alternative trade patterns and the productivity of the automobile industry. The main results of the theoretical model show that network trade results in a higher profit level than dedicated trade as a rule, although network trade is less stable than dedicated trade. Empirical study reveals that increasing network trade leads to higher productivity.