DFOB is responsible for 10% of UK milk production
More than 90 jobs are under threat at a Denbighshire cheese-making and packing plant.
Milk Link bought the creamery in Llandyrnog in June saving 160 jobs after the co-operative Dairy Farmers of Britain (DFOB) went into receivership.
But Milk Link says it now plans to stop packing cheese at the factory and switch the process to an existing plant in Oswestry, Shropshire.
The union Usdaw has criticised proposals to make 93 workers redundant.
Milk Link said it was consulting staff, but said the jobs could be lost.
DFOB went into receivership at the beginning of June, placing jobs at its creameries in north and south Wales in jeopardy.
The co-operative had lost a lucrative supermarket contract and was struggling to pay its 1,800 member farmers a competitive price for milk.
However, Milk Link stepped in to save the Denbighshire factory, but a subsequent review has concluded it has "high and unviable staffing levels."
In a statement, Milk Link said: "As a result of its findings, today Milk Link has announced proposals which will assist in returning the site to profitability, with the aim of providing it with a long-term sustainable future.
"The review confirmed that at acquisition Llandyrnog's cheese-making and packing operations were loss-making, despite it paying a below the market average price to farmers for milk.
"Further to this, the creamery had high and unviable staffing levels and suffered from considerable volatility in the volumes of cheese made, as a result of the creamery being used by its previous owners as a 'balancing facility' to process excess and often inconsistent volumes of milk into cheese."
Milk Link plans to stop packing cheese in Llandyrnog and will focus solely on producing the product.
The company added: "If the proposed measures are confirmed then regrettably a total of 93 jobs will potentially be made redundant."
Usdaw national officer John Gorle said: "Our officials received several phone calls at about 5.30pm last night to tell us that Milk Link was going to announce at 6pm that 93 of the 160 jobs at their Llandyrnog site are to be made redundant.
"It is deplorable that in 2009 companies in Britain still behave in this manner, giving us no notice that they are to virtually close a factory which has supported the whole of a north Wales community for decades.
"We were not even given the chance to be there to support our members in the worst moment of their working lives.
"The employees, the union, local politicians and the wider community feel misled and let down."