The decision follows on from last year’s management buyout, with chief executive Anita Murray having since purchased the remaining minority shares.
She says: “After 19 years at the helm of this fantastic agency I’ve decided that it’s time to step down.
“I feel hugely privileged to have worked in such an amazing industry with so many talented and passionate people.
“The time is right for me to leave Anita, Dave [Greenwood, managing director] and the team to write the next chapter for the agency.”
Browne has helped lead the agency to become a leading operator in the food, drink and hospitality industry.
A member of the Arena committee for several years, she was named Hospitality Action’s Ambassador of the Year 2005, and her name is regularly associated with initiatives involving young people, chef skills and boosting the hospitality industry’s reputation.
Since 2008 she has been listed in the ‘Who’s Who of Britain’s Business Leaders’ and in 2011 was voted as one of the top 100 most influential women in Hospitality, Leisure, Travel & Tourism.
Anita Murray said: “Karen is highly respected in the industry. She has been a great chief executive and chairman for William Murray Communications and a trusted adviser to the team, our clients and me personally.
“Likewise, Stephen has used his industry and commercial knowledge to steer William Murray to success. It’s been a privilege to work with them over the last nine years.”
Murray and Greenwood will continue in their board roles, with new board director appointments likely to announced in the future.
Founded in 1989, today agency’s clients include Unilever Food Solutions, UCC Coffee UK & Ireland, Quorn, Bestway Wholesale, Santa Maria, Elior, and BRITA Professional.