London - Mercedes technical head Paddy Lowe is departing the Formula One team and has started on a period of 'gardening leave' before a likely move to rivals Williams.
Mercedes made the long-awaited announcement on Tuesday, wishing him well but without revealing any future plans.
Lowe's move to Mercedes-powered Williams is likely to be the first of several that will ultimately see Williams's Finnish driver Valtteri Bottas travelling in the other direction to replace retired world champion Nico Rosberg.
The Briton, who has helped Mercedes win three successive constructors' and drivers' titles, started his F1 career at former champions Williams in 1987 and spent six years there before moving to McLaren.
The 54-year-old joined Mercedes in 2013, six months after the arrival of Britain's triple world champion Lewis Hamilton, as part of the senior management team.
Rosberg retired unexpectedly last December five days after winning his first title.
"I have had a fantastically successful and enjoyable three and a half years at Mercedes working with an incredible team of people," Lowe said in a Mercedes statement.
"I am now looking forward to a new challenge and wish everyone well at Mercedes."
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Mercedes, which has plenty of engineering expertise on board, is expected to recruit former Lotus and Ferrari technical head James Allison, who left the Italian team last year.
The team said it would continue planning for the new season under engineering head Aldo Costa, performance director Mark Ellis, chief operating officer Rob Thomas and technology director Geoff Willis.
"Paddy has played an important part in our success during the past three and a half years and we thank him for his contribution to this significant chapter in Mercedes' motorsport history," said team boss Toto Wolff.
"Success in Formula One is not about single individuals but about the strength in depth and technical capability of an organisation.
"We have the talent in place to continue our success of recent years and we plan to build upon it in 2017 and beyond."
Mercedes was dominant in 2016, winning 19 of 21 races and starting all but one on pole position.
Media reports have suggested Lowe could become team principal at Williams but team sources told Reuters that was not on the cards.
Deputy principal Claire Williams, who effectively runs the family-owned team, told Reuters last year that her 74-year-old father Frank "will always be our team principal".