Robert Wiseman Dairies has warned its current year operating profit could be hit by as much as £8.5m.

The dairy company, which today revealed an 11.3% drop in full-year operating profit to £31.6m for the year to 29 March, said profit would be hit by cost increases, a delayed recovery in selling prices and a shortfall in bulk cream revenues.

Last year's fall in operating profit was because of a £6.1m penalty from the Office of Fair Trading, which would be paid later this year, and re-organisational costs, Robert Wiseman said.

Pre-tax profit fell 15.6% to £29.2m on sales up 19.3% to £722m.

Sales had been driven by increased selling prices, with revenue per litre of liquid milk sold averaging 47.6p per litre, up from 41.5p a litre last year.

“Despite short-term margin pressures, we are confident that the business is in good shape with the Brigwater facility now operational,” said chairman Alan Wiseman.

“We strongly believe this will provide us with the platform to continue our successful growth in the period ahead,” he added.