The holding company's eagerly anticipated trading update reveals that public relations and public affairs revenues reached £201.6m from £167.2m one year earlier. Excluding the effect of currency movements. PR and public affairs were harder hit than advertising and media, which dropped by 3.9 per cent.
Sorrell said that the UK and North America were the hardest hit regions for PR and public affairs. The Middle East and Latin America demonstrated strong growth, with continental Europe flat.
Branding and identity, healthcare and specialist communications (including direct, internet and interactive) was the hardest hit division, revenues falling five per cent.
Overall, the company reported a revenue slump of almost six per cent, excluding the impact of the acquisition of research giant TNS.
Its business in the US felt the downturn most keenly, with the UK less affected and Asia Pacific, Latin America, Africa and the Middle East the best performing.
WPP's results come one day after rival Omnicom, which owns Ketchum, Fleishman-Hillard and Gavin Anderson. The US-based company reported that PR revenues slumped by 17 per cent during the first quarter of 2009, significantly worse than the decrease of 12.8 per cent in advertising revenue.
WPP also warned of a profits shortfall in 2009, after indicating that Q1 like-for-like revenues will be below budget.