Aon plc and U.S. middle market property/casualty broker NFP Corp. cleared a regulatory hurdle in Aon's proposed $13.4 billion acquisition of NFP as a waiting period expired under the U.S. Hart-Scott-Rodino Antitrust Improvements Act of 1976. The transaction is expected to close in mid-2024. Until closing, Aon and NFP will continue to operate independently, the companies said in a joint statement.