"Mr Oliver has worked tirelessly for his members, but at the same time he has earned widespread respect from employers given his honesty, integrity and respect for the views of others.
"Ai Group has been on the opposite side of the table to Mr Oliver in many major industrial disputes and union campaigns, but there have also been many issues on which we have worked closely together, including superannuation, skills and work health and safety.
"No matter our differences, Mr Oliver has always been open, accessible and willing to listen and to seek to understand views different to his.
"Personally I thank him for our close working relationship which has helped resolve many issues behind the scenes and out of the public spotlight.
"Mr Oliver will be a big loss to the trade union movement, and Ai Group wishes him the very best for the future," Mr Willox said.
Media enquiries: Tony Melville – 0419 190 347