The performance far outstripped that of WPP’s advertising and media interests, which only registered a six per cent rise.
The firm said in a statement that its strong showing in PR and public affairs reflected the boom in web-based social networking.
The company did not provide results for individual agencies and the results were unaudited.
Group revenue rose two per cent to £2.921bn. Pre-tax profit rose 13.7 per cent to £338m in constant currencies.
In WPP’s 2006 annual figures PR and public affairs accounted for 10.1 per cent of revenue. WPP’s agencies include Hill & Knowlton, Ogilvy and Finsbury.