The move follows the resolution of a stand-off with rebel shareholders who delayed the deal because they were unhappy with their terms. The sale is due to be completed this Friday (5 September).
The group will now focus on expanding its reach in the US and Asia, where it is considering various acquisitions.
It is particularly keen to add more data and analytics skills, expand its digital offering and deepen its content resources. For example, in June, Engine bought The Intelligence Group, a consumer insight company, and merged it into its US creative agency Noise.
The group will also focus on integrating its family of agencies and explore collaborations such as joint pitching. All Engine’s New York-based businesses will be moved into one building.
Last Thursday, more than 97 per cent of Engine shareholders approved the acquisition by Lake Capital, a private equity company. The rebel shareholders – former employees of Engine – had previously blocked the deal because they felt it favoured those who were still at the group.
It is understood the conflict was resolved after the rebels were offered terms on par with current employees.
Peter Scott, the Engine chief executive, said: "This is the beginning of the next stage of the Engine growth story."
Terry Graunke, the chairman and co-founder of Lake Capital and new Engine Group executive chairman, said: "Integration is the first order of business. We already have companies co-pitching. We will spend the resources necessary to get this right."