The 51-year-old will be charged with putting the firm back on track after nine months, enlivened by an catastrophic IT systems failure, a profit warning, 400 redundancies and the departure of chief executive Robin Southwell.
Sources close to the move said that Skanska was "not best pleased" with losing one of its star players. Clarke, a senior vice-president, has left just months after new Skanska chief executive Stuart Graham completed a worldwide shake-up of the business.
Selected from a shortlist of six candidates, Clarke will move to Atkins on 1 October, replacing acting chief executive Mike Jeffries. Jeffries will remain as chairman.
Jeffries pre-empted criticism that Atkins had brought in a contractor to run a professional consultancy by noting that Terrel Wyatt, Atkins' chief executive from 1987 to 1992, was a contractor.
He said: "He came from Costain and transformed our business. And we are doing a certain amount of contracting now anyway."
Jeffries added that Clarke's breadth of experience across the construction sector would benefit a multidisciplinary consultant such as Atkins – as well as working for contractor Skanska, Clarke was trained as an architect and was employed by Canary Wharf's original developer, Olympia & York.
Keith has one of the best analytical minds in planning and architecture
George Iacabescu, Canary Wharf
He said: "Keith has exceptional professional and international expertise and he has also worked on the clients' side with Olympia & York.
Asked to describe Clarke's attributes, Canary Wharf chief executive George Iacabescu, who worked with him at Olympia & York, agreed with Jeffries. He said: "Keith has one of the best analytical minds in planning and architecture and is an extremely sharp-minded and likable person."
Clarke said: "The skills and experience of the staff are the group's prime asset and I look forward to working with Michael Jeffries, [finance director] Stephen Billingham and the rest of the management team." He added that the group's core businesses were strong.
Clarke's appointment marks the culmination of a nine-month search to replace Southwell, who resigned at the end of September after Atkins issued a shock profit warning.
In January, Atkins believed that it had found a replacement but the preferred candidate rejected the offer. Atkins ordered its recruitment consultant to restart the search and 20 to 30 candidates were interviewed before a shortlist of six was drawn up in April.
City sources this week suggested that a management buyout of Atkins' US arm Benhams is nearing completion.
The rise of Keith Clarke
- 1993 Appointed deputy managing director of Trafalgar House Corporate Development.
- February 1996 Made chief executive of Trafalgar House’s construction division.
- March 1996 Norwegian engineering group Kvaerner acquires Trafalgar House for £904m.
- July 1996 Appointed executive vice president of Kvaerner Construction.
- 1999 Made chairman of the Major Contractors Group.
- August 2000 Kvaerner’s construction division bought by Skanska. Made chief executive of Skanska Construction.
- July 2001 Clarke appointed chief executive of Skanska UK.
- February 2002 Clarke becomes executive vice president, joining main board of Skanska.
- June 2003 Atkins appoints Clarke as chief executive, starting in October.