Hough is the second most senior person at the agency after chairman Tim Delaney.
Hough has been with the agency for five years, joining from Lowe, where he was managing director of the Amsterdam office. His career has also included stints at Leo Burnett, BMP DDB, and he started out at J Walter Thompson in 1980.
Details of his next job have not yet been revealed, although Hough said that it was still in the communications industry.
"I thought it was time for a bit of a change. I was approached, which is always flattering, at a time where I was wondering if there is life beyond advertising," he said.
Hough's departure is one of several changes to the senior management line-up at the agency over the past 18 months or so.
Chairman Bruce Haines left Leagas Delaney in December 2001, with reports that his relationship with Delaney had deteriorated. A month later, group media director Jerry Fielder and finance director Eric McClean announced they were to leave.
Earlier in the week, Leagas Delaney said that the management of its San Francisco office were in the process of an MBO, and that it planned to set up a full service office in New York City.
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