Supplier Environmental Assessment in Sustainability Reporting: Evidence From Top <scp>ESG</scp> ‐Performing Brazilian Firms

ABSTRACT This study examines the maturity of supplier‐related environmental disclosures in sustainability reports of top environmental, social, and governance (ESG)‐performing Brazilian companies. A content analysis of 67 reports from firms listed on the Corporate Sustainability Index (CSI) was conducted using the CRITIC method to weight disclosure criteria and Grey Fixed Weight Clustering to classify maturity levels. Results reveal substantial variation: nearly 60% of firms fall into the low‐maturity cluster, while companies in regulated or internationally scrutinized sectors, such as banking, pulp and paper, and food processing, demonstrate higher maturity. Findings highlight sectoral disparities, the influence of regulatory and market pressures, and gaps between stated sustainability goals and supplier accountability. The study advances debates on supply chain environmental accountability, offers a replicable framework for benchmarking disclosure maturity, and provides practical insights for managers, ESG analysts, and policymakers to strengthen transparency, due diligence, and alignment with sustainability commitments.