UPDATE 2.45pm: MACA managing director Doug Grewar has resigned from the company to make way for the return of Chris Tuckwell.
Mr Grewar took over from Mr Tuckwell in October 2012 when he resigned to work for Ausdrill as its Africa-based chief operating officer.
Non-executive chairman Andrew Edwards thanked Mr Grewar for his efforts over the past 19 months and said he was delighted to welcome back Mr Tuckwell.
"Chris is of course very familiar with MACA's clients and operations," he said.
"His recent experience in Africa has added to his already considerable experience."
MACA said Mr Tuckwell's appointment date and terms of his contract would be announced when they were confirmed.
Mr Tuckwell's notice period with Ausdrill ends at the end of July.
Ausdrill said it was considering various options regarding the appointment of a suitable successor to Mr Tuckwell and would make a further announcement when a decision was made.
MACA shares closed down two cents at $2.14 while Ausdrill shares were off 0.5 cents to 94.5 cents.