Robert Wiseman Dairies has said that its sales volumes and turnover for the six months to 30 September are slightly above forecast and that it expects to deliver first-half results ahead of market expectations.

However, in a trading statement released this morning, the dairy company also warned that high energy and plastic costs could “potentially erode the recovery in margins”.

It added that this week it had signed an agreement to pack all the Rachel's brand organic milk from November 2006.