A post-auction battle has broken out over the purchase of Dean Foods Co. ’s assets, with a group of bondholders saying it might put forward an alternative deal in the bankruptcy and with others saying the sale process was unfair, WSJ Pro Bankruptcy reported. A group of Dean bondholders said in a court filing it has been exploring all options — including seeking help from the federal government — to obtain funding for its own reorganization of the milk processor. A hearing into whether the $433 million sale of most of the assets of Dean Foods to winning bidder Dairy Farmers of America Inc. should be approved is scheduled for Friday in U.S. Bankruptcy Court in Houston. The deal, if completed, would unite two dairy giants. Dean, the top U.S. milk processor by sales, filed for bankruptcy in November after struggling with slumping consumer demand for traditional cow’s milk. Dairy Farmers is the largest U.S. dairy cooperative by membership.