Aon Acquisition Antitrust Fight Spotlights ‘Big Customer’ Market

The Justice Department’s suit to block Aon Plc‘s $30 billion proposed acquisition of Willis Towers Watson Plc raises the question of whether servicing large, multinational companies for their insurance demands is a market distinct enough to warrant antitrust protection.

Aon and Willis Towers Watson, the second and third biggest firms in the global insurance brokerage business, are part of the “Big Three” alongside leading player Marsh & McLennan Cos., the DOJ alleged in its June 16 antitrust complaint.

The proposed acquisition would reduce the large-customer market to a “Big Two,” the DOJ’s Antitrust Division warned. The “Big Three” ...