Advertising revenue at the UK's largest newspaper publisher, Trinity Mirror, fell 11.8 per cent in the first four months of the year, as the online advertising market continued to steal income from print.

The company, which publishes the Daily Mirror among more than 240 local, regional and national titles, told shareholders at its annual general meeting on Friday that only property listings had dodged the slump, with recruitment advertising revenue falling 22.6 per cent and motoring 12.9 per cent. The drop at national titles was 14.1 per cent but advertising in regionals fared slightly better, sliding by 10.4 per cent.

"The difficult advertising market conditions experienced in 2005 have continued into 2006," Trinity-Mirror said in a statement. "Management continues to run the business on the assumption that the advertising environment will remain very challenging."

In April, the company rolled out property sites in 10 newspaper regions, building on its 2005 acquisition of smartnewhomes.com. It also bought job search platform hotgroup in the same year, in an effort to broaden its revenue base from newspaper adverts to internet classifieds, which many see as a more measurable advertising medium.

Alarmed by the migration of advertising from print to digital, the newspaper sector has launched a counter-offensive to retain the confidence of marketers.

The Newspaper Marketing Agency, which comprises the UK's biggest newspaper groups, last week published the findings of a £14 million study which "clearly proves that newspapers are an effective yet under-used medium for brand campaigns". The study provides "a tool-kit for the industry to re-evaluate its assumptions about the role of newspapers in advertising campaigns", the NMA said.