Regulatory processes and debates are often informed by competition assessments issued by antitrust agencies, who advocate against potentially anticompetitive governmental regulations. While these opinions are usually not binding for regulators, the participation of antitrust agencies may have significant influence over the outcome of regulatory processes. This article examines whether antitrust agencies use their competition assessments to link regulation and development. The research addresses two research questions: first, do antitrust agencies consider development, directly or indirectly, as a guiding criterion in their competition assessments of regulatory projects? And second, what does development mean for these agencies in the context of competition assessments? A case study approach was used to answer the research questions, analyzing the cases of three countries of Latin America: Argentina, Colombia, and El Salvador. Based on the examination of over 300 competition assessments published by the antitrust agencies and on the semi-structured interviews of antitrust agencies’ former and current officials, we report four main findings: (i) the studied agencies frequently used the term “development” in their competition assessments to explain the policy context, the objectives of the regulatory proposals, and the potential benefits of competitive markets.; (ii) the meaning of “development” that prevailed among the three cases studies corresponds to a narrow understanding of “economic development” (e.g. a synonym of economic growth); (iii) the case of Colombia stands out because some of the competition assessments explicitly recognize the importance of broader conceptions of development, including sustainability; and, (iv) competition advocacy was used by the studied agencies to link regulation and development through their reports and recommendations on regulatory projects.