On July 26, 2021, Aon and Willis Towers Watson announced they would no longer pursue a merger in the face of litigation filed by the U.S. Department of Justice to block the transaction. The $30 billion deal, which was announced on March 9, 2020, allegedly would have combined the second and third largest of the "Big Three" global insurance brokers, creating the world's largest insurance broker ahead of Marsh McLennan.