The news hit Trinity Mirror's share price this morning, sending shares down 8.5% to 370p from last night's close of 405p.
Advertising revenue growth across the regional newspapers for the 26-week period is estimated to be 4.5%. The strong first quarter was offset by a weaker second quarter, with an estimated 2% increase in the April to June period.
This growth was principally driven by recruitment advertising, which is estimated to have grown by 17% in the 26-week period, with the first three months of the year seeing growth in excess of 20%. This has since eased off to 13% in June.
Advertising revenue for Trinity's national newspapers -- The Mirror, Sunday Mirror and Sunday People -- grew by nearly 2% in the first half. However, an estimated decline of 4% has been seen in the April to June period, with the month of June experiencing a 10% fall.
Conditions in the Scottish market, where Trinity owns the Daily Record and Sunday Mail, has suffered from very difficult trading conditions, with an estimated decline in advertising revenue of 3.5%, which includes a decline of 6.5% during the April to June period.
In a statement, the company said, "Current trading conditions remain volatile, with very limited visibility and no signs of a return to the level of advertising growth that was seen in the earlier part of the year. Cost reduction methods are being applied throughout the group."
Trinity Mirror is due to report interim results on July 27.