Greenhill managing director Richard Hoyle led the team advising Aegis on its £3.2bn sale to Dentsu.
Hoyle has been a long-standing adviser to Aegis, having worked on the agency’s £210m purchase of Australian ad firm Mitchell Communication and last year’s sale of market researcher Synovate to Ipsos.
The 36-year-old, who joined Greenhill from Credit Suisse in 2000 after a position at Barclays de Zoette Wedd, also advised Robert Wiseman Dairies on a £279.5m sale to German group Müller.
Greenhill has recently advised debt-laden Yell Group on the troubled firm’s capital restructuring operation.
Greenhill advisers Pieter-Jan Bouten and Hiroto Yamada worked under Hoyle on the sale.
Tim Wise and David Harvey-Evers at JP Morgan Cazenove also worked with the company on the deal.
Dentsu’s acquistion of Aegis was advised by banking giant Morgan Stanley in the international operation.
Hironobu Wakabayashi advised on the Japanese firm’s deal from Tokyo while Ian Hart led the team from London with Laurence Hopkins and corporate broker Andrew Foster.
Hart, who was co-head of European mergers and acquisitions at Citigroup before moving to Morgan Stanley in 2009, has also recently advised oil giant Royal Dutch Shell on the oil giant’s £1.12bn offer for Cove Energy.