Ogilvy UK chief executive Annette King has departed the advertising group after 18 years to become CEO of Publicis UK. The group’s chairman and chief for EMEA Paul O’Donnell will take on the role while a replacement is found.

In a letter to staff, Publicis Groupe chief executive Arthur Sadoun described King as “one of the most recognised leaders in the industry” and praised her “managerial skills, the loyalty and passion she inspires in her teams, the trust she has gained with her clients”.

She will join the French holding company in 2018 after 12 months gardening leave, when she will take on responsibility for all UK operations across the four “hubs” in its Power of One model (Publicis Communications, to Publicis Media, Publicis.Sapient and Publicis Health).

“She will be responsible for ensuring that we bring to life our vision of being our clients' indispensable partner in their transformation,” said Sadoun, who added that she will report directly to him and join the global management committee.

“To do this, Annette will work closely with all of our UK leaders to drive greater integration across our capabilities, transform our relationship with existing clients, win the trust of new ones and of course cultivate and attract the best talent across our agencies and disciplines.”

The appointment comes less than two weeks after reports surfaced elsewhere saying Steve King would be taking "responsibility for the entire UK business".

However, Sadoun clarified that he had “agreed to act as executive sponsor while we identified the right CEO at Groupe level for the market”.

“He's already kickstarted this model in the UK and as a member of the Directoire and CEO of Publicis Media globally he has been actively involved in the recruitment process and will be a real support to Annette," he said.

The Drum understands her departure came as a shock to Ogilvy bosses.

King had only recently returned from a three-month sabbatical taken on the back of a series of high-profile business wins for the agency.

Under her stewardship it won the integrated creative, loyalty and and media account for British Airways after losing different parts of it in the years prior, as well as new clients including Boots and Vodafone.

A succession plan has not been revealed, however chairman and chief executive EMEA Paul O’Donnell said she is leaving the agency “in great shape.”

“Over the past 18 years Annette has made a significant contribution to Ogilvy in many capacities," he said.

"She leaves Ogilvy UK in great shape, with an outstanding leadership team in place across the breadth of the agency, so we wish her all the best.”