SYSTEM TRANSACTION ADMINISTRATOR
In a central system, the entity or neutral body, in charge of providing services to the system's members. It is in charge of performing specified tasks on behalf and under the responsibility of the system's direct members. It can be a matching engine, a settlement engine, or a financial institution. It also maintains accounts or netting positions for the direct members of the system, registers transactions, performs checks and validations, and manages the settlement cycle or other value added processes, as specified in the functional specifications of the system. Euroclear Clearing and Settlement glossary