The case dates back to the period 2000 to 2004 during which Amcor was alleged to have overcharged Cadbury for its corrugated fibreboard packaging.
The Amcor board told the Australian competition authorities in 2004 that its employees had been involved in price fixing with Visy Group.
For blowing the whistle on the cartel, Amcor gained immunity from prosecution, while Visy was found guilty and fined AUS$36 million in one of the most high profile cases on its kind in Australia.
When the Australian Competition and Consumer Commission won its case against Visy it said the case was "one of the most serious, blatant cartels" it had ever pursued.
Amcor did not escape from the cartel unnoticed. Cadbury sued the company saying that it had been overcharged by Amcor for its packaging supplies.
The case had been due to begin in the Federal Court in Melbourne on Wednesday, but was instead settled out of court.
Amcor has never defended itself in public regarding the price fixing allegations so the court case would have been the first time.
The packaging company was facing the possibility of a heavy legal bill as Cadbury was demanding that it repay AUS$236m for losses and damages resulting from the alleged Amcor and Visy cartel.
The case would have been the biggest-ever claim heard in Australia for cartel activity.
The terms of the final out of court settlement were not revealed but Amcor published a statement saying the resolution is expected to have no material impact on the financial position of the company.
Amcor also said the parties were finalising the specific terms of the settlement and that court proceeding had been stood over for a period of seven days. A further announcement will be made when those terms are finalised.