In this study the researcher attempts to advance the understanding of the structure of firm buying centers for air travel services. First, an attempt is made to find empirical support for the proposition that firm air travel service buying centers can be grouped on the basis of their size, degree of complexity, centralization, and formalization. The study investigates the relationship of size, structure, and technology of the organization as a whole to the structure of the buying center. Diagraphs, or pictures representing the members of the buying centers, and the communication flows between those members, allow the researcher to record three constructs of buying center complexity: lateral involvement, vertical involvement, and connectedness. The size of the buying center is defined as the number of people within the organization who participated in the buying process from the reservations phase to the final payment of the supplier. The degree of centralization is determined by the number of communications between the travel manager and other buying center members. Formalization of the buying center was operationalized as the percent of written versus verbal communication in the buying process, the extent to which the process was governed by rules and policies, and the degree of compliance with policy. Significantly different mean values were found in buying center size and the degree of written versus verbal communication across the three cluster analysis-derived groups. None of the other buying center variables were found to differentiate the groups. Of all the organizational variables, only firm size, as measured by the absolute value of air travel purchases per year, was found to be a better-than-chance predictor of group membership. Additional research on participation during the contract negotiation phase is suggested. It is further proposed that future researchers wishing to study corporate travel in an industrial marketing context begin to study influence on, in addition to participation in, the buying process. It is further suggested that these issues should be investigated in the context of global as well as domestic organizations and evaluated on a longitudinal basis. / Ph. D.