Business-to-business electronic commerce (B2B e- commerce) is booming and is increasingly used by organisations worldwide to improve the effectiveness and efficiency of their supply chain. Electronic marketplaces (e-markets) are the latest development in B2B e-commerce. The vision is to develop e-markets in which all stages of the procurement process - information, negotiation, settlement and after-sale - are automated and services can be dynamically composed. Despite great potential for supply chain optimisation, there are drawbacks relating to human acceptance of, and trust in, these new Internet-based technologies. These arise from the delegation of the end-to-end procurement task to software agents. This study set out to address this issue by exploring i) user needs of a (futuristic) fully automated B2B e- marketplace and ii) product requirements that will satisfy them. To this end, seven representatives of different elements of the supply chain in the freight industry were interviewed in two stages (using a semi- structured and a scenario-based fully structured approach to interviewing, respectively). The focus of the main usability study was to try and ground the arising user needs of delegation to software agents in the trust literature. The qualitative data analysis revealed the following user needs: control as substitute for trust, human intervention in non- routine situations, development of personal relationships, impersonal trust as substitute for personal trust, and system observability. These are discussed in terms of implications for user-centred prototype design and possible contamination effects of the data by data collection, coding and analysis. 45 Pages