Neutral Access Networks (NAN) have appeared as a new model to overcome some restrictions and lack of flexibility that are present currently in broadband access networks. NAN brings new business opportunities by opening this market to new stakeholders. Although the NAN model is accepted, there are some technical issues that need to be resolved to facilitate wider NAN deployment. This paper proposes a new technical approach to neutral access networks, which is based on Carrier Ethernet technology. The proposal allows the user to independently select both the service provider and the network operator that will be used to deliver the service. To achieve this, a shared infrastructure is needed, which takes NAN as reference model. The main contributions of this proposal are the following: an Ethernet-based approach for neutral access networks; a mechanism for users to select which network operator is used to access each/target service provider; and an AAA (Authentication, Authorization and Accounting) infrastructure and access control policy profile to control service delivery over selected/requested NAN. Finally, a working prototype is described for validation of the proposal.