The survey showed that only 40 per cent of the 100 leading press and public relations agencies in question offer a range of digital services.
Leanne Rinning, Online PR Manager at bigmouthmedia said: 'The PR industry is certainly beginning to come to terms with online PR and social media, no doubt motivated by the proven benefits of digital campaigns, but it is less clear whether the sector fully understands the discipline.
'It is not simply a case of replicating your offline press releases on the web, but requires specialist expertise and an informed understanding of how people engage with news, brands and products on the web.'
The survey also found that the number of agencies publishing blogs has doubled, but that 78 per cent of those agencies do not produce their own.
London agencies fared a little better than regional outfits - 48 per cent of London firms offer online PR with 30 per cent publishing their own blogs.