Under the agreement, Dairy Farmers of America, a farmer-owned co-op, would pay $425 million to acquire 44 of Dean Food’s facilities, as well as the real estate, inventory and equipment necessary to operate them. To move forward, the deal must be approved by the bankruptcy court overseeing Dean Foods as well as by regulators, who have been investigating the potential merger for months.

So far, much of the antitrust scrutiny has focused on the co-op’s evolving role in the American milk business. Two decades ago, Dairy Farmers of America was founded to help small farmers market their raw milk to dairy processing companies like Dean Foods, which prepare milk for distribution to retailers.

But over the years, the co-op, which now has more than 14,000 members, has also invested heavily in processing, meaning it buys some of the raw milk that its own marketing branch sells. Those investments have created a conflict of interest, some dairy farmers argue, because processors benefit from lower milk prices, while farmers benefit from higher ones.

Dean Foods, the largest milk processor in the United States with a little under 60 manufacturing facilities and a portfolio of well-known brands like TruMoo and Lehigh Valley, filed for bankruptcy protection in November, hurt by changing consumer habits and a growing market of milk alternatives.

Dairy Farmers of America’s plan to acquire a large portion of Dean Foods’ assets would significantly expand its processing operations, heightening the conflict of interest, critics of the merger say.