Almost all votes cast at a meeting in Melbourne this morning backed the deal, which values the marketing and communications firm at A$363m.

Mitchell shareholders have the option of cashing out at A$1.20 per share, or they can swap their stock for Aegis shares.

The group works predominantely with clients in areas such as communications strategy, media buying and planning and digital media and marketing, but it also maintains consumer insight research capabilities within its agencies Mitchell & Partners and MPG.

Founder Harold Mitchell said ahead of the vote: “Today we move into a new era… This is a great opportunity for us to move onto the world stage… Aegis has a turnover of some $20bn, that’s 50% bigger than the entire Australian advertising industry…

“I hope many of you come along with us. I hope the broader Australian community goes out to the world as we have. And those that aren’t with us, I hope that we have your complete support as you watch us move forward.”