Macquarie Group has announced today that its chairman David Clarke has formally stepped down from his post to address some personal health issues.

The company said in announcement that Mr Clarke has formally resigned and will be replaced by Macquarie's Lead independent director Kevin McCann.

The investment bank said in an issued statement that Mr McCann paid tribute to Mr Clarke for his 40-year contribution to Macquarie.

"When David joined Hill Samuel Australia, the company that was to become Macquarie had just 12 staff. Today Macquarie has 15,500 employees operating out of 70 offices in 28 countries,'' he said.

"David was appointed Joint Managing Director of Hill Samuel Australia in 1971. In 1977, he was appointed Managing Director and in 1984 Executive Chairman. David was Executive Chairman fof Macquarie Bank from its formation in 1985 until March 2007, when he ceased executive duties.'' Mr McCann said.

Mr McCann served as acting Chairman of Macquarie Group and Macquarie Bank from 27 November 2008 to 30 August 2009 when Mr Clarke took a leave of absence, the statement said. Mr McCann is also chairman of Origin Energy, a director of BlueScope Steel and a member of the Council of the National Library of Australia and the University of Sydney.

Macquarie Group managing director and chief executive officer, Nicholas Moore, also paid tribute to Mr Clarke's ''long and sustained contribution to a bank: "David should be immensely proud - as we are - of his contribution to Macquarie, which has been able to successfully compete with the strongest players in financial markets globally, delivering strong returns for shareholders and unrivalled opportunities for our people.''

Under his leadership, the (Macquarie) Foundation and Macquarie staff have contributed more than $145 million to community groups globally as well as thousands of hours in volunteering activities.