Service providers purchase rights to distribute content on the content market. They create content-based services and provision them to their users on the electronic communications market. Current business relationships on the content market are based on long-term contracts between service providers and content providers. The purpose of the approach proposed in the dissertation is to introduce dynamics into the content market and to encourage competition between content providers. Special intention is paid to the negotiation phase of the proposed Content e- Trading Transaction Model. In that phase, the service provider runs a multi-attribute reputation auction, providing the opportunity to select a winner of the auction based on the attributes of the offered content as well as on the content providers’ reputation. Reputation tracking is introduced in order to identify reliable content providers and to reduce damages that occurred as a result of the content provider’s late delivery of the purchased content. Namely, service providers advertise the appearance of new content and are thus affected by late deliveries. The implications of late deliveries may include a decrease in user’s interest regarding content-based services and/or users switching to other service providers. In the implemented multi-agent system, Service Provider Agent and Content Provider Agents act as representatives of the participants on the modelled electronic content market while the Broker Agent represents the market. The functionality of the implemented multi-agent system for content trading and the efficiency of the proposed multi-attribute reputation auction are experimentally verified in two case studies.