In this paper, a Multi-Agent System (MAS) platform for semantic service integration based on the Semantic Web Services Initiative Architecture (SWSA) is discussed. We define a software architecture in order to provide concrete realization of the SWSA. The architecture fullfills fundamental requirements of the SWSA's sub-processes. Software agents are employed in automatic discovery and execution of the Semantic Web Services within this architecture. We also elaborate implementation of SWSA's sub-processes (service advertisement, discovery, engagement and enactment) taking the main components of the defined architecture and their interactions into consideration. Hence, the developers can easily utilize semantic web service technologies by using this flexible and extensible platform.