Firms coordinate their actions with industry peers, and this affects product market competition. We investigate how financial reporting transparency affects industry coordination using the cartel setting. Economic theory predicts that transparency might either prolong cartel duration through increased contracting efficiency or destabilize cartels due to earlier detection of deviating members. We test these predictions using firms that were indicted by the European Commission for anticompetitive behavior between 1980 and 2010. Using reporting under international accounting standards (IFRS or U.S. GAAP) as our measure of reporting transparency, we find that following international accounting standards decreases cartel duration. We show that this finding is explained by the requirement to report segment disclosure, which provides a means for the verification of agreed-upon sales for a given product or region. Consistent with the view that transparent reporting leads to earlier detection of deviating members, we further show that transparency lowers cartel duration when the opportunity costs of cooperation and the likelihood of cheating are high.