As access to data is critically important in our society, we are witnessing the development of a data market ecosystem that supports data trade and sharing between data providers and data consumers. Intermediaries in this context are important as they provide value-added services that enable the parties to operate on the data market as they support the transactions between the main actors. In this paper, we propose an agreements framework with services enabling the collaboration between the parties together with the enabling mechanisms. It relies on a data marketplace used as a trusted third-party handling all transactions between the parties. In order to provide a high level of trust, transparency and fairness in a multi-stakeholder ecosystem, we rely on a distributed ledger approach to enable monitoring of the activities within the ecosystem as well as storing the agreements established in the data marketplace.