Run by high-profile businessman Martin Sorrell, the UK group said investments in technology had helped reduce costs, while the plunge in the pound following Britain’s vote to leave the EU had helped reported revenues.
In the long term, however, Mr Sorrell said clients were cautious about big investments as they wait to see what type of deal Britain can secure with its global trading partners.
The firm has little pricing power, he said, and the second half could be tougher than the first due to challenging comparative figures from last year.
“In April to June we saw a slowdown in the UK before the vote and after the vote in July we saw some strengthening,” Mr Sorrell, a leading advocate of EU membership, told Reuters.
“So it’s mixed at the moment. It’s still very uncertain because what business wants is certainty and what the government wants is room to manoeuvre.”
WPP offers branding, media planning, market research and consultancy services, with clients including Ford, Unilever, L’Oreal, and Tesco. The group has been outperforming rivals in recent years, doing particularly well in the US.
The owner of agencies Ogilvy & Mather, Young & Rubicam and JWT reported first-half like-for-like net sales up 3.8%, compared with analysts’ expectations of around 3.2%, due to strong demand in North America and continental Europe.
Reported revenue was up 11.9% to £6.5bn (€7.5bn), helped by the weakness of the pound against the dollar and euro. On a like-for-like basis, growth hit 4.3%.
The group also nudged up its full-year revenue forecast, predicting growth of “well over” 3% compared with “over” 3% before, sending its shares as much as 6.3% higher at one stage to a record high of 1,857 pence.
The shares closed at 1,780 pence, up 2% on the day.
WPP said its British operations had traded more strongly in July than the previous quarter, which it said perhaps reflected a “post-Brexit vote recovery” driven by a weaker pound.
“WPP’s first-half results are encouragingly strong with a decent beat on an underlying basis amplified by beneficial forex moves,” said Citi analysts, who have a buy rating on the stock.
The first-half update follows an impressive performance from French rival Publicis which reported strong underlying sales growth in July.