Terence Kyle, Linklaters' managing partner for the Americas, is set to retire
Kyle, 56, who has been with the firm throughout his entire professional life, is due to leave Linklaters on 31 July.
During his 34 years there, the capital markets specialist served as managing partner, and later chief executive, when he was one of the partners to drive through the European alliance strategy.
Kyle, responsible for the Americas since September 2001, said: "I just feel I've been at the firm for a long time and want to do something else. I've no idea what, but I've made a contribution and now I want to move on."
The Americas, and the task of growing the US lawyer count, will now fall to managing partner Tony Angel.
Kyle said he would take some time before making his next move, but said he would consider taking on a non-executive role at a corporate.