Berkshire Hathaway Inc. has guaranteed the unsecured debt of Precision Castparts Corp. Therefore, we withdrew our 'AA-' issuer credit rating on Precision Castparts and raised the rating on its unsecured debt to 'AA' from 'AA-', the same as the rating on parent Berkshire's unsecured debt. Berkshire Hathaway has provided a guarantee of Precision Castparts' unsecured debt. This is consistent with our criteria for shifting the evaluation of the creditworthiness of the obligations from the primary obligor to that of the guarantor (a "rating substitution"). Therefore, we raised the rating on Precision Castparts' unsecured debt to that on Berkshire's unsecured debt and withdrew our issuer credit rating on the company. General Criteria: Group Rating Methodology, July 1, 2019 Criteria Corporates
