Eccleshare moved back to London from New York earlier this year after serving as the chief executive of Clear Channel Outdoor.
On his return to the UK, he said: "London is still, for me, the home of some of the greatest creative work in the world.
"In outdoor, the innovation we see in the UK is probably greater at the moment than anywhere else in the world."
Last week was Eccleshare's 25th time at the Cannes International Festival of Creativity. He said the festival has evolved to be a "more productive week" for agencies, media owners and advertisers.
Watch Eccleshare's full interview with Campaign above.