Speaking at Advertising Week Europe, Sorrell said that content was one of the biggest growth areas for WPP, in a session alongside the News Corp chief executive, Robert Thomson.
Sorrell said of the growth of brand-funded content: "I think it’s symptomatic of our industry. We’ve becoming one of the biggest creators of content in the last few years. We’re not originating technology, we’re applying it."
Sorrell said that content, including native advertising, was one way in which companies such as WPP could challenge Google, which he described as "all-powerful."
He said: "You could argue that Google is the most powerful company in the world: it certainly makes the most revenue. It has the five things it is good at: search, display, video, social and mobile. Its future is about intelligent search. Coming back to native and content, these are ways that we can compete with a company like Google.
"Ten years ago, people were saying Google would put us out of business. We’re still here. It doesn't mean we don’t have our challenges, but we’re still here."
During the session, Sorrell also stressed the importance of transparency in media, and said WPP’s digital media trading platform Xaxis was transparent because it revealed the price charged for programmatic ads.
In comparison, he said, Google was "opaque" because it did not reveal how its search algorithm worked.
Sorrell also discussed the youth video network Vice Media, in which his holding group WPP has a stake.
He said Vice, which is set for soaring revenues of around $500 million in 2014 according to a report from Bloomberg last week, made his companies "think about content more in an online way".
Sorrell said that Vice was "flavour of the month" and encouraged agencies in his Group M media arm to adapt to the demand for online content.