Ad giant WPP said “China and the internet” remain its main opportunities for growth after reporting a 30% rise in pre-tax profits in the first half of this year.

The company, which has made a string of investments in online ventures in the past few months, said its direct marketing and digital activities now account for 20% of revenues.

WPP boss Sir Martin Sorrell said they could provide one third of its earnings in the next five to ten years.

In its results statement, WPP said: “The two critical strategic opportunities for our clients, media owners and ourselves … could be glibly described as China and the internet.”

Overall, the company posted a 30% rise in pre-tax profits for the first half of 2006, to £287 million. Revenues for the six months rose 16% to £2.86 billion.

Sorrell also said earnings in 2007 would be boosted by the run up to the Olympics and the US presidential campaign.

WPP recently announced the purchase of ad-backed online game publisher WildTangent, as well as a partnership with online reputation monitoring firm Visible Technologies.