Parcel volumes over the summer at UK Mail were below expectations, causing turnover to slip 1% year-on-year in the first half of its financial year.

For the six months ending 30 September UK Mail said that the first quarter showed good revenue performance, but the second quarter has been more challenging with parcels volumes below expectations, particularly in the latter weeks of the period.

“It is too early to assess whether this represents a more persistent trend and therefore the extent of any possible impact on the full year outcome,” it said in a statement to investors today.

Turnover in its mail business was down 6% due to a shift in its customers towards UK Mail’s customer direct access service, which has lower revenue per item.

UK Pallets, however, suffered as increasing network costs resulted in “the overall performance being below expectations”.

“Action is currently being taken to address this,” the statement warned.

Shares fell 14.8% to 472p in early morning trading.