Mining Services CEO Quits
It has been a tumultuous period for Macmahon and the mining services sector, with work drying up as the mining boom has ended and miners take work in-house and cut costs.
No reason was given for Mr Carroll's departure, which was immediately effective.
Late last year, Perth-based Macmahon downgraded revenue expectations for 2014/15 by $150 million - from $750 million to $1 billion to $750-$850 million.
That was due to a dispute in Mongolia in which Macmahon says it is owed $US30 million for work at a coal project by state-owned company Erdenese Tavan Tolgoi.
That dispute could cost far more, with the total value of Macmahon's contract - with a joint venture partner - more than $US500 million ($A617.97 million).
The company is also facing a possible class action from investors dating back to 2012, who said it did not disclose details about losses on a rail project for Rio Tinto in the Pilbara.
The company's chairman Jim Walker will act as executive chairman until a replacement for Mr Carroll is found.
Macmahon said there would be no change to Mr Walker's remuneration and it would not replace departing director Barry Cusack - who also resigned on Thursday - to save costs.
"The board is committed to implementing cost saving measures across the business as the company navigates the current suppressed market for mining services," Mr Walker said.