Construction giant Leighton Holdings has announced the appointment of Stephen Johns as the company’s new chairman after the surprise resignation of chairman David Mortimer.


Mortimer announced his resignation from the Board of the Company with immediate effect. An Independent Non-executive Director since 1997, Mr Mortimer was elected Chairman of Leighton in June 2000.


“The Board of Leighton thanked Mr Mortimer for his leadership and invaluable contribution to the Company as a Director and particularly as Chairman, especially through the demanding period of the last 12 months. During this time Mr Mortimer 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,” the company said in an announcement to the ASX.


Mr Mortimer’s resignation ends a 14 year stint at the construction company.


In another surprise development for the company, Hamish Tyrwhitt has been selected to as the company’s new Chief Executive Officer and Managing Director, replacing David Stewart.


Currently head of Leighton’s Asian operations, Mr Tyrwhitt will take the role of chairman immediately.


The terms and conditions of Mr Tyrwhitt’s employment are in the process of being finalised and a detailed summary of the contractual arrangements will be provided


Bob Cooke, currently General Manager Commercial for Leighton Asia, will be appointed Acting Head of Leighton Asia / Leighton Asia, India and Offshore.