The chairman position will be taken over by current CEO Marcelino Fernandez Verdes.
“It has been a privilege to be involved with Leighton for the last nine and a half years and as chairman for the last year. However it is now time for me to retire from corporate life and to hand over to a new team.” Humphris said.
The reshuffle follows a partial takeover bid from Hochtief, the majority shareholder.
Verdes is also the CEO of Hochtief.