Abstract: The paper develops a distributed systems architecture for dependable Internet based online auctions, meeting the requirements of data integrity, responsiveness, fairness and scalability. It is well-known that a tree-based, recursive design approach caters well for scalability requirements. With this observation in mind, the paper develops an approach that permits an auction service to be mapped on to globally distributed auction servers. The paper selects a suitable auction model that treats sellers and buyers symmetrically. This symmetry enables a computational node to play at one level of the tree the role of a seller by dealing with a group of potential buyers as well as to play the role of a potential buyer at the next higher level. Such a symmetric auction (also known as a double auction) is used for supporting a standard auction to be carried out in a hierarchic manner. An architecture is developed and basic algorithms and protocols are presented.