The chilled foods group Northern Foods has said its third quarter profits will be flat after a late rush for Christmas orders led to higher costs.

The firm supplies own-label products to many of the UK's biggest food retailers, including Tesco, Sainsbury's, Marks & Spencer and Asda.

Total sales grew by 6.5% on a like-for-like basis for the three months to 31 December.

But the strong sales figures were offset by higher costs after Northern Foods had to hire in extra labour to meet a late surge in Christmas orders.

Profits were also hit by start-up costs at the firm's new plants in Hull and Longford, although the company said sales were ahead of expectations in both factories.