기업합병․분할과 2025년 개정 상법상 이사의 충실의무

This article examines the implications of newly amended Article 382-3 of the Korean Commercial Code (KCC), effective in 2025, which expressly imposes a fiduciary duty of loyalty owed by directors to shareholders, with particular attention to its impact on corporate mergers and demergers. The centerpiece of the amendment is the director’s duty to ensure the fair treatment of shareholders (Article 382-3(2), latter part). Unlike the traditional principle of shareholder equality, which is typically confined to formal, mechanical, and procedural equal treatment in the exercise of shareholder rights, the duty of fair treatment focuses on achieving substantive fairness among shareholders, particularly between controlling and minority shareholders. The article argues that when directors make decisions that favor the controlling shareholder in situations where the interests of shareholder groups diverge, the burden of proof should shift to the directors to demonstrate the fairness of the transaction. The amendment also calls for a integrated analysis approach, under which a series of related transactions is analyzed collectively to determine overall fairness, rather than in isolation. In practice, debates over the fair treatment of shareholders have arisen chiefly in the context of corporate restructuring, where wealth transfers among shareholder groups are at stake. Accordingly, this article concentrates on the implications of the amendment for mergers and demergers. With respect to unfair mergers, Article 382-3(2) first clarifies that shareholders of the disappearing company may pursue ex post damages against the directors for approving a merger unfavorable to disappearing company. However, to enhance ex ante protection - especially the availability of preliminary injunctions to suspend unfair mergers - a separate statutory provision recognizing a “right to freeze the merger process” would be desirable. In contrast, for mergers disadvantageous to the surviving company, the amendment does not significantly alter the prevailing doctrine. Under existing law, an unfair exchange ratio unfavorable to the disappearing company constitutes harm to its shareholders, whereas an unfair ratio unfavorable to the surviving company constitutes harm to the company itself; the amendment leaves this distinction intact. This article nevertheless argues that, in corporate actions that alter the shareholder composition any underpriced issuance should be regarded as causing harm to the existing shareholders rather than the company. Regarding divisive restructurings designed to facilitate pyramidal control structures, the integrated analysis approach becomes particularly important because such structures are usually completed through a sequence of steps. First, in the case of a split-off followed by an initial public offering of the subsidiary, the resulting dilution of minority shareholders’ value and the enhancement of controlling shareholder influence may constitute a violation of the director’s duty of fair treatment. Second, where a spin-off is followed by an exchange tender offer, the second-step transaction may, in substance, amount to a third-party allotment in favor of the controlling shareholder. Under the amended provision, directors should bear the burden of demonstrating the necessity and fairness of such an exchange tender offer. As with mergers, this article also suggests that the legislature should consider introducing an explicit “right to freeze the demerger process” to facilitate judicial review of unfair demergers through interim relief.