Greater antitrust enforcement is argued to have positive correlations with the promotion of international trade. By 2019, the US, the EU and China, as global trade powers, have formed and strengthened bilateral antitrust cooperation to seek greater enforcement. However, the impact of such development on international trade has remained underexamined. The article argues that irrespective of their different legal forces, the US-EU, US-China and EU-China antitrust cooperation share convergences at the optimum and minimum levels. Based on the case study of the US, the EU and China’s regulations of the international Liquid Crystal Display (LCD) panel cartel, the article illustrates that as the effects doctrine continues to serve as the main normative value underpinning antitrust cooperation, matured competition regimes lack the incentive to share information with new regimes, competition regimes converge to apply comity restrictively and the consultation mechanism plays a limited role in holding the sides accountable under bilateral cooperation. Consequently, international antitrust remains fragmented, positing restraints to trade. The article calls for reconsideration of the effects doctrine as part of the transnational normative repertoire shaping bilateral antitrust cooperation and for devising policy tools to guarantee minimum information exchange among agencies. US, EU, China, International Antitrust, Bilateral Cooperation, Exchange of Information, Confidentiality, Comity, Consultation