Mitchinson has more than 27 years' experience at UK mobile companies, including stints with Nokia and Samsung Electronics, where he became vice-president in 2008. He joined Carphone Warehouse in 2011 as group MD, before becoming VP of the UK arm of Chinese telecoms firm Huawei Technologies.
In his new role, W said Mitchinson will focus in particular on developing the commercial side of the agency and support its growth internally.
Warren Johnson, founder and CEO of W, said: "Mark’s appointment comes at a crucial time, and his expertise both in building companies and growing them internationally will be an invaluable asset not only to W’s ambitious expansion plans, but also as we continue to optimise the service we deliver to our clients."
Mitchinson said: "PR remains critically important to the vast majority of brands across a number of wide and varied industry sectors. Having spent the majority of my career on the client side, I understand the importance of genuine partnership and return on investment. I’m very excited about the opportunity of taking up the position as chairman of W and working alongside Warren and his team of professionals in the pursuit of excellence."
According to PRWeek UK’s Top 150 Consultancies Report, W’s fee income grew 45 per cent in 2014/15 to almost £3.4m, coming in at number 62 on the list.
During the year, W won a place on the Unilever roster and an assignment from Live Nation for its Wireless festival.