개정 상법상 이사의 충실의무와 공정거래법상 사업기회 제공 - 대법원 2025. 6. 26. 선고 2024두34382 판결을 소재로 -

The SK-Siltron case drew significant public attention as the first instance in which sanctions were sought against a controlling shareholder for the use of a business opportunity. In June 2025, the Supreme Court of Korea annulled the corrective order and administrative fine imposed by the Korea Fair Trade Commission, holding that the transaction at issue did not constitute an “offering of business opportunity” under the Monopoly Regulation and Fair Trade Act (the “MRFTA”). Shortly thereafter, in July 2025, the amended Article 382-3 of the Korean Commercial Act explicitly expanded directors’ duty of loyalty to shareholders. Against this backdrop, new questions arise as to how related-party transactions-including the offering or use of corporate opportunities-should be evaluated under the revised duty of loyalty framework. This article examines the SK-Siltron case as a basis for comparing and analyzing the legal treatment of the use and offering of business opportunities under both the Commercial Act and the MRFTA. It explores how the revised duty of loyalty may influence the interpretation and enforcement of the MRFTA, particularly in cases involving intra-group transactions. By tracing the legislative background and underlying rationales of the two doctrines within their respective legal regimes, the article argues that the amended Commercial Act and the MRFTA now share clearly overlapping regulatory objectives: namely, preventing unjust transfers of wealth within corporate groups and protecting minority shareholders. Building on these findings, the article contends that further in-depth discussion is required to foster interpretative harmonization on points of divergence between the two legal frameworks-particularly regarding board review standards for the use and allocation of corporate opportunities and the scope of fiduciary duties-and to enhance the coherence of conflict-of-interest regulation from an integrated perspective.