(19)Requiring a regular rotation of credit rating agencies is proportionate to the objective pursued. The requirement only applies to registered credit rating agencies, which are regulated and which provide a service affecting the public interest (credit ratings that can be used for regulatory purposes) under the issuer-pays model and for a particular asset class (re-securitisations). The privilege of having its services recognised as playing an important role in the regulation of the financial services market and being approved to carry out this function, gives rise to the need to respect certain obligations in order to guarantee independence and the perception of independence in all circumstances. A credit rating agency which is prevented from rating re-securitisations from a particular originator would still be allowed to rate re-securitisations from other originators as well as rating other asset classes. In a market context where the rotation rule applies to all participants, business opportunities will arise since all credit rating agencies would need to rotate. Moreover, credit rating agencies can always issue unsolicited credit ratings on re-securitisations from the same originator capitalising on their experience. Unsolicited credit ratings are not constrained by the issuer-pays model and therefore are theoretically less affected by potential conflicts of interest. For the clients of credit rating agencies, the maximum duration of the contractual relationship with a credit rating agency and the requirement to employ more than one credit rating agency also represent restrictions on their freedom to conduct their own business. However, those restrictions are necessary on public-interest grounds considering the interference by the issuer-pays model with the necessary independence of credit rating agencies to guarantee independent credit ratings that can be used by investors for regulatory purposes. At the same time, those restrictions do not go beyond what is necessary and should rather be seen as increasing the creditworthiness of re-securitisations towards other parties, and ultimately the market.