Journal of Historical Research, Law and Policy 3115-7505 In Press 2027 11 01 Expansion of Commercial Companies and the Requirements for Preserving a Competitive Market Structure: A Comparative Analysis of Concentration Control and Dominant Position in Iranian, U.S., and European Union Law Expansion of Commercial Companies and the Requirements for Preserving a Competitive Market Structure: A Comparative Analysis of Concentration Control and Dominant Position in Iranian, U.S., and European Union Law 1 16 EN Journal Article 2026 06 16 <p>Effective competition in commercial markets serves as a key driver of innovation, price reduction, and improvements in the quality of goods and services. However, in the course of their development and expansion, commercial companies often employ strategies such as mergers, acquisitions, and the abuse of a dominant position, which may disrupt the competitive structure of the market. Adopting an analytical-comparative approach, this study examines the requirements for preserving a competitive market structure in the context of the expansion of commercial companies across three legal systems: Iran, the United States, and the European Union. The findings indicate that, under U.S. law, the Sherman Act and the Clayton Act, with their emphasis on economic efficiency and consumer welfare, provide robust regulatory mechanisms and effective civil and criminal enforcement measures for controlling market concentration and market dominance. In the European Union, the structural approach based on Articles 101 and 102 of the Treaty on the Functioning of the European Union provides a coherent and supranational framework focused on competitive fairness and the preservation of market diversity. By contrast, despite the enactment of the Law on the Implementation of the General Policies of Article 44 of the Constitution and the establishment of the Competition Council, the Iranian legal system continues to face structural challenges, including weak enforcement mechanisms, a lack of institutional independence, and a shortage of specialized judicial precedents. Drawing on the successful experiences of the two more developed competition-law regimes, the present study proposes reform measures aimed at achieving an appropriate balance between corporate expansion and the preservation of effective competition in the Iranian market.</p> https://jhrlp.com/index.php/jhrlp/article/download/446/417