Kevin Russell, the chief executive of mobile operator 3UK, is to leave the group this summer after four and a half years to return with his family to Australia.
He will be replaced by the company's chief financial officer David Dyson, who has worked closely with Mr Russell in his various roles for the past nine years.
While it came as a surprise to some in the market, a spokesman for the group said the company had been working on succession plan for the past 18 months.
Mr Russell was appointed UK chief executive in 2007. He overhauled the business, turning it profitable three years later. He said he will take six months off work when he returns to Australia.Reuse content