In Zenith Corp. v. Hazeltine, 395 U.S. 100, 110, 23 L. Ed. 2d 129, 89 S. Ct. 1562 (1969) Zenith had sued a subsidiary company, alleging that the parent and the subsidiary had committed certain Sherman Act violations. The parent company was not made a party to the suit. The trial court entered judgment against both the subsidiary and the parent company, and the parent appealed. The Supreme Court held that the judgment against the parent was improper because the parent had not been made a party to the suit.