AnimalFeeds International Corporation (AnimalFeeds) (plaintiff) used maritime shipping company Stolt-Nielsen, S.A. (Stolt-Nielsen) (defendant) to ship its goods pursuant to a standard maritime contract known as a charter party. The specific charter party used by AnimalFeeds was called the “Vegoilvoy.” In 2003, the U.S. Department of Justice found that Stolt-Nielsen had engaged in an illegal price-fixing conspiracy. When AnimalFeeds learned of this it brought a putative class action suit against Stolt-Nielsen in federal district court, asserting antitrust claims. Thereafter, AnimalFeeds provided notice to Stolt-Nielsen that it demanded class arbitration. The parties agreed to allow a panel of three arbitrators to decide whether class arbitration was permitted under the contract, which was “silent” with respect to class arbitration. After a hearing, the arbitrators concluded that the contract’s arbitration clause permitted class arbitration. The district court vacated the decision, concluding that the arbitrators had disregarded aspects of federal maritime law. AnimalFeeds appealed. The court of appeals reversed and found that because Stolt-Nielsen failed to cite any authority applying the federal maritime rule of custom and usage against class arbitration, the arbitrators’ decision was not in manifest disregard of federal maritime law. The United States Supreme Court granted certiorari to review.