He had been an independent non-executive director since 1997 and was elected chairman in June 2007.
The board thanked him for his leadership and invaluable contribution as a director and particularly as chairman, especially through the demanding period of the last 12 months. During this time he dealt with a number of challenges including the transition to a new chief executive officer, the takeover of Leighton’s major shareholder and the April 2011 profit downgrade and subsequent capital raising. Last week, Leighton Holdings reported an after-tax loss of AU$409m (£260m) for the 2010/11 financial year, with the problems also affecting parent company Hochtief.
“Whilst the last 12 months have been very demanding, I am pleased to be leaving after the Board has addressed legacy issues and has been able to announce a positive forward outlook for the Company. I wish the Leighton Group well in its future endeavours,” said Mr Mortimer.