By Kate Holton

LONDON (Reuters) - The unassuming Mark Read will embark on the unenviable role of running WPP this week, tasked with reshaping a group at the center of seismic industry change following the departure of the world's most high profile advertising boss Martin Sorrell.

Read, a 51-year-old with experience across strategy and digital operations, is expected to be named WPP's second-ever CEO in the coming days after persuading the board he had what it takes to lead the world's biggest advertising company.

Sorrell quit the British group in April following a complaint of personal misconduct, which he denied, and after a year-long sharp downturn in trading sparked by cautious clients and competition from Facebook, Google and new consultants.

Read, appointed to run the business as a joint chief operating officer until a permanent CEO was found, told Reuters in June that WPP needed radical change to remain relevant to clients but that they could evolve their way there, suggesting a review of some assets but no major break up.

Clients, current and former WPP executives and analysts have told Reuters they also expect a program of evolution not revolution, slowing down the hunt for acquisitions and re-engineering the agencies to provide a more joined up service.

"For any leader coming into any business the most important thing is to have respect," Jon Williams, a former chief creative officer at WPP agency Grey, told Reuters.

"Because of Mark's operational delivery and because he's got a personal relationship with a lot of the business leaders, he's got that respect. He can hit the ground running."

Sorrell built the world's biggest advertising and marketing services company by taking over some of the most storied names in the industry - JWT, Grey, Ogilvy and Y&R - and combining them with PR agencies, market research and media planning groups.

Headquartered in London, it now owns some 400 businesses around the world, set up to compete with each other for work.

That has fallen out of favor with clients, however, as they want fewer teams providing an array of complimentary services, rather than multiple teams and multiple strands of work.

Sorrell had already talked about the need to break down barriers but Read is expected to go further. He and his co-chief operating officer Andrew Scott have been asking WPP executives what works and what doesn't since they stepped up in April.

RIGHT HAND MAN

"He's listened, he's gone out of his way to make sure people understand that he wants to be collaborative, that he's a peer," the CEO of one WPP agency, speaking to Reuters on the condition of anonymity, said.

"He knows the business as well as anyone, having been at the right hand of Martin all this time. And he knows that the solution to our future is not these acquisitions that keep feeding the growth."

Read, a father of two young children, strikes a very different pose to Sorrell, who he wrote to asking for a job in 1989.

Where Sorrell was an outspoken CEO, commenting on everything from the Chinese economy to influencers on Instagram, the softly-spoken Read adopts a lower profile, trying to avoid photographers at the end of the recent annual general meeting.

Like Sorrell a graduate of Cambridge University and Harvard, Read is described by colleagues as a good listener and delegator, with no obvious ego. When talking to journalists he takes time to think before answering questions.

The chief marketing officer of one of Britain's biggest companies said Read should not be underestimated.

He relayed how Read, when running WPP digital agency Wunderman, had approached him to explain what he could provide if and when they next put their ad contract out to tender. He stayed in regular touch - a job normally farmed out to more junior staff - and 18 months later Wunderman won the deal.

"He is an incredibly personable collaborative, non-aggressive individual who prefers to work through his acumen, his intelligence, his intellect, not through his relationship and networks," the CMO said.

"He's more shrewd than you may at first realize when you get the soft handshake and mild manner. Don't be fooled."

Read will need all his acumen to hand when he takes over the top job, perhaps on Tuesday when WPP publishes first-half results, knowing that Sorrell, a large WPP shareholder, will be watching after he launched a new competitor.

According to those spoken to by Reuters Read will be met by a groundswell of good will. The WPP agency CEO said: "For the first time since I've been here I got an email from the person in charge of the company that began with: how are you doing?

"And I was like: holy shit, because he actually wanted to know."

(Reporting by Kate Holton; Editing by Ros Russell)