In a trading update to the City, the Sir Martin Sorrell-led group said UK revenue totalled £251.1m in Q1 2009, up 16% on a constant currency basis - which excludes the effects of currency movements - from £216.4m in the same period last year.
WPP revealed that its advertising and media investment management operations, which as well as media agencies such as Mindshare includes its various creative shops such as Grey and JWT, were least affected by the economic downturn. It added that global revenue from these operations slid 3.5% in Q1 2009 to £812.1m.
Combined, these operations were WPP's single-biggest revenue sector in Q1, accounting for 38.4% of revenue. WPP did not break out financial performance of individual creative or media agencies.
The global decline reflected, WPP said, "cuts in client spending in reaction to the global financial and economic crisis".
It said these economic pressures was most keenly felt in the US, although the UK was "less affected" and Asia Pacific, Latin America, Africa and the Middle East were the "least affected".
Looking ahead, WPP warned that "the first half of 2009 will clearly be very difficult, with the second half, although continuing to be tough, likely to improve relatively". It added that any recovery "will probably come in 2010".