Robert Wiseman Dairies has reported an increase of almost 30% in its full-year earnings.

The dairy’s preliminary results revealed pre-tax profits of £34.6m, up from £26.7m last year.

Total sales increased by 6.5% to £605.3m, which incorporated a 5.9% increase in sales volumes to 1.46b litres.

Alan Wiseman, Wiseman chairman, said the company had gradually rebuilt its operating margin despite a “challenging environment”.

In the past year the diary secured new supply contracts with One Stop convenience stores and Booths, increased its contract with the Co-Op supermarkets and signed an organic milk contract with Sainsburys, which is set to begin in the autumn.

The firm’s future would be “heavily influenced” but the success of utilising its £46m Bridgewater dairy, which is set to open in December, Mr Wiseman added.

“We are confident we can continue our steady progress in the period ahead.”