Sir Martin Sorrell has hinted at what he will do next after leaving advertising group WPP following allegations of personal misconduct.

Speaking to Luma Partners Chief Executive Terence Kawaja at the company's Digital Media Summit in New York on Tuesday, Sorrell implied he would set up a new agency.

"What I'm looking at, and what I will focus on and try to do again — as we did in 1985 — is look at where are the opportunities from a technological point of view, and look at where are the opportunities from a geographic point of view and put the two together," he said, according to a Wall Street Journal report.

"That may sound very simplistic, but I think actually, at the end of the day, it isn't."

Sorrell, 73, bought a controlling stake in WPP — then Wire and Plastic Products — in 1985 and turned it into the world's largest ad agency holding company. Speaking at the Techonomy NYC 18 conference last week, he said: "I'm going to start again."

"I'm not going to go into voluntary or involuntary retirement," he added.

Sorrell left WPP last month amid a misconduct investigation. "After being extracted, I can see much more clearly where there are the growth pieces (in advertising) and where there are the challenges," he said at the Techonomy event.

He acknowledged that the traditional advertising business — which is under pressure from tech companies like Google and Facebook as well as consultancies — is capable of reinvention. "All the people running holding companies understand this," he added.

Big-spending ad clients such as Procter & Gamble are looking for cheaper and quicker solutions, with P&G's Chief Brand Officer Marc Pritchard criticizing agencies for having "excess management, buildings and overhead," at a conference last month.

Sorrell will also speak at the Cannes Lions International Festival of Creativity in June, which is set to be a "candid discussion about the marketing industry issues of today," according to a report on industry website Ad Age.