The U.S. Court of Appeals for the Second Circuit on Monday refused to revive a civil antitrust case alleging that a contingent of banks had agreed to fix the trillion-dollar market for bonds backed by foreign governments and multinational institutions.

A three-judge panel of the Manhattan-based appeals court ruled that plaintiffs in the sprawling class-action lawsuit could not plead a plausible conspiracy to rig prices for the U.S. dollar-denominated “supranational, sub-sovereign and agency bonds,” which are typically sold to investors at break-neck speed on a decentralized secondary market that is known for its lack of transparency.