The sale of the Constar assets was through a court-supervised bankruptcy process which involved an auction for the assets.
Rumours are circulating Amcor was outbid by another company at an auction on February 6 and details of that company will be released soon.
Amcor confirmed it had entered into an asset purchase agreement with Constar last December.
According to Constar, the transaction was subject to higher and better offers and approval of the Bankruptcy Court, as well as other customary closing conditions.
Constar had planned to sell most of its assets in two separate auctions, one for its US assets and another for assets or stock of affiliates in the UK and the Netherlands.
FoodProductionDaily.com has contacted Amcor and Constar for further comment.