Cecil Balmond is to head the new Europe and building division that brings together the UK, Russia, Poland, Germany, Holland, Italy, Spain and Turkey.
Arup chairman Bob Emerson circulated a memo to staff on Friday saying the appointment was a result of the restructuring.
He said: "I am personally very distressed that anyone in Arup should have vindictively passed information to the media and to add insult to injury, not only got their facts totally wrong, but also given an incorrect impression that is potentially damaging to the firm and to the individual concerned." An Arup spokesperson further confirmed this view saying: "He is moving to the States to run our fastest growing and most important market. He was chosen as the most suitable and qualified person." The third new division in the restructured Arup is the specialist practices division, for specialists working across geographic boundaries. This division will be led by Turlogh O'Brien.