The US Department of Justice filed a civil suit on Wednesday to block the proposed merger of Aon and Willis Towers Watson, arguing that combining two of the Big Three insurance brokers would create an anticompetitive “behemoth.”

Many observers thought the government would allow the deal. Regulators in Europe, where both companies also operate, had indicated that they were likely to approve the merger, which would create the world’s largest insurance brokerage.

   NYT