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3. External Ratings-Based Approach (SEC-ERBA)

C 52/2017 STA Effective from 1/4/2021

22.To be eligible for use in the securitisation framework, the external credit assessment must take into account and reflect the entire amount of credit risk exposure the bank has with regard to all payments owed to it. For example, if a bank is owed both principal and interest, the assessment must fully take into account and reflect the credit risk associated with timely repayment of both principal and interest.

23.A bank is not permitted to use any external credit assessment for risk-weighting purposes where the assessment is at least partly based on unfunded support provided by the bank itself. For example, if a bank buys ABCP where it provides an unfunded securitisation exposure extended to the ABCP program (e.g., liquidity facility or credit enhancement), and that exposure plays a role in determining the credit assessment on the ABCP, the bank must treat the ABCP as if it were not rated. The bank also must hold capital against the liquidity facility and/or credit enhancement as a securitisation exposure.

24.External credit assessments used for the SEC-ERBA must be from an eligible external credit assessment institution (ECAI) as recognized by the Central Bank in accordance with the Central Bank standards on rating agency recognition. However, the securitisation Standards additionally requires that the credit assessment, procedures, methodologies, assumptions and the key elements underlying the assessments must be publicly available, on a non-selective basis and free of charge. Consequently, ratings that are made available only to the parties to a transaction do not satisfy this requirement. Where the eligible credit assessment is not publicly available free of charge, the ECAI should provide an adequate justification, within its own publicly available code of conduct, in accordance with the “comply or explain” nature of the International Organization of Securities Commissions’ Code of Conduct Fundamentals for Credit Rating Agencies.

25.Under the Standards, a bank may infer a rating for an unrated position from an externally rated “reference exposure” for purposes of the SEC-ERBA provided that the reference securitisation exposure ranks pari passu or is subordinate in all respects to the unrated securitisation exposure. Credit enhancements, if any, must be taken into account when assessing the relative subordination of the unrated exposure and the reference securitisation exposure. For example, if the reference securitisation exposure benefits from any third-party guarantees or other credit enhancements that are not available to the unrated exposure, then the latter may not be assigned an inferred rating based on the reference securitisation exposure.