One of the important challenges for manufacturers and distributors of autoparts is the coordination of multiple sourcing areas where their international suppliers are located. The objective of this research is the design of a service transportation network that takes into account the time shipments are held at customs and transshipment terminals, as well as the possible delays due to the use of different transportation modes. To assure the best performance of the whole transportation network, a bi-criteria optimization model was formulated, the two criteria considered were cost and time. The solution to the model was the structure of the transportation network to be used by a manufacturer of auto parts located in the Toluca industrial zone; this firm imports auto parts produced by suppliers located in the United States (E.E.U.U.) and commercializes them among multiple automakers. The structure of the optimization problem was analyzed to obtain a convenient separable arrangement and then the problem was solved by using Lagrangian relaxation. A set of possible efficient solutions for the structure of the transportation network was generated by using the weighting method and the ¿-constraint method; the resulting solutions represent the set of best alternatives from which the logistics managers may choose the service network that best attends the needs and logistics performance goals of the firm.