EU Set to Approve Aon-Willis Merger; More Concessions Unlikely: Reuters Insurance broker Aon is set to gain conditional EU antitrust approval for its $30 billion bid for Willis Towers Watson without having to offer more concessions, people familiar with the matter said. Aon, which clinched the deal a year ago to create the world’s largest insurance broker ahead of Marsh & McLennan Companies Inc., offered concessions to the European Commission earlier this month. Following feedback from rivals and customers last week, the EU competition enforcer has asked for some tweaks but is unlikely to ask for more concessions, the people said.