<![CDATA[A cartel is one form of prohibited anti-competitive practice because it allows business actors to control prices, the distribution of goods, or market conditions through agreements among competitors. Such practices may undermine the competitive process and cause harm to consumers. In Indonesia, the prohibition of cartel practices is governed by Law Number 5 of 1999 concerning the Prohibition of Monopolistic Practices and Unfair Business Competition as an instrument of legal protection while also promoting a healthy competitive environment. This study aims to analyze the legal nature of cartel agreements under Indonesian competition law and examine the relevance of the application of cartel law in the ratio decidendi of Supreme Court Judgment Number 1114 K/Pdt.Sus-KPPU/2021 in light of Law Number 5 of 1999. This study employs normative legal research using a statute approach and a conceptual approach. The findings indicate that Law Number 5 of 1999 has not been fully effective in preventing cartel practices by business actors. The findings also indicate that the ratio decidendi adopted by the Business Competition Supervisory Commission and the Supreme Court is consistent with the provisions of Law Number 5 of 1999. Such consistency rests on identifying price signaling as a form of coordination among competitors, thereby forming the basis for applying the per se illegal approach in adjudicating the case. These findings underscore the importance of the consistent application of competition law to enhance the effectiveness of law enforcement against cartel practices in Indonesia.]]>
