The company posted a $1.2 million net loss for the six months to September 30, compared with a $17 million net profit for the same period the year before.

Warrnambool Cheese and Butter general manager Richard Wallace attributed the slide to a near halving of the prices of key global dairy commodities. He said the price the processor paid farmers for their milk did reflect the global dairy rout, further eroding the company's bottom line.

"The decrease in profits is mainly due to declines in global international commodity prices and a high raw-milk cost relative to market conditions," he said.

"[And] the depreciation in the Australian dollar only partially offset the effect of the above."

Mr Wallace's comments came two months after Theo Spierings, the chief executive of Fonterra, the world's biggest dairy exporter, said the Australian farm-gate price was too high and called for an "honest debate about what is being earned in the market".

All of Australia's main milk processors have matched the farm-gate price of Australia's biggest dairy company, Murray Goulburn.

The co-operative's managing director. Gary Helou, has defended its forecast $6.05 a kilogram milk solids payout. But Mr Helou warned at Murray Goulburn's annual general meeting last week the price could dip to $5.60-$5.90 a kilogram if the company's "expectations do not materialise".

Mr Wallace said although global dairy prices had begun to recover, which should improve returns in FY16, the "cost of raw milk relative to market conditions remains high".

He said WCB, which Canadian dairy giant Saputo controls with an 88 per cent stake, would not pay shareholders a dividend, investing in the business instead.

"WCB intends to accelerate its growth activities, invest in capital projects, increase manufacturing capacity, grow milk intake and create new opportunities," Mr Wallace said.

The company also incurred an after-tax cost of $3.2 million after it bought Lion's everyday cheese business, which includes the Coon and Cracker Barrel brands, for $137.5 million in May.

WCB's revenue firmed 4.7 per cent to $307.1 million.

Meanwhile, Fonterra finalised the sale of its strategic 9 per cent stake in Bega Cheese on Thursday. The trans-Tasman company sold its shareholding for $74 million to fund growth elsewhere in the business.

Chief financial officer Lukas Paravinci said the sale would not change Fonterra's commercial relationship with Bega, which includes a licence on the Bega brand and supply contract for cheese.

"The Bega brand has an important role in our cheese portfolio where we are a market leader, and we will continue to build on our relationship with Bega which goes back more than a decade," Mr Paravinci said.