Intellectual Property Rights (IPR) management in c-publishing is becoming a key issue for its full deployment. There is a real and urgent need to solve the problems associated with multimedia content copyright control that the spreading of the Internet and the WWW has created. Although many technical solutions to the problems already exist, there is still a lack of an efficient and agreed business model for c-commerce of c-publishing. Apart from introducing copyright information in the content to sell, there are other new specific needs related to IPR management in c-publishing. One of them is the possibility of negotiating the copyright conditions when buying multimedia material. This material could be directly bought by end-users, or, more interesting, by other publishers. An example of this situation could be the negotiation between an intellectual rights holder and a prospective publisher. In the paper, we present a specific approach to this IPR need, which is based on the use of metadata for representing IPR features, and on the specification of a protocol for negotiation of copyright at the purchase moment. Furthermore, the paper introduces the issues associated to IPR negotiation in a multi-broker environment.