The ACC board has issued a statement expressing sadness at the resignation of chief executive Ralph Stewart.
Mr Stewart quit on Wednesday, saying he was prompted by the departure of chairman John Judge on Tuesday and directors John McCliskie and Rob Campbell.
In a statement, Mr Judge said board members believe the vision and strategy planned for ACC by Mr Stewart, which has been signed off, are full of promise.
He said Mr Stewart's leadership was already starting to change the culture at ACC and his plans to improve services to claimants and levy payers were in the process of being introduced.
