Glanbia has sustained a significant drop in sales for the past six months as the Irish group continues to suffer from slumping global dairy markets.

The company said it had suffered “a very substantial first-time loss” at its Irish diary ingredients arm but insisted an ongoing programme of cost-cutting “would counterbalance [the] unprecedented market circumstances”.

Group sales fell 14.6% to €944.9m, while operating profits were down 15.4% to €47.8m. The group’s debt, meanwhile, more than doubled to €546.5m thanks primarily to its purchase of Optimum Nutrition in August 2008.

“It has been, without doubt, a difficult six months,” said managing director John Moloney.

“International dairy prices were sharply down on 2008, resulting in a dramatic reduction in dairy product returns, and US cheese prices reached historic lows. While we remain cautious in our outlook today, we expect the overall rate of decline to moderate in the second half.”