Radcliffe was appointed CEO of HRG in 1997, and led the company’s repositioning as a focused corporate services group.
Radcliffe said: "The transaction will create a truly world-class company capable of delivering significant benefits to clients, colleagues and suppliers."
He was appointed to the HRG board in 1989, having joined the group originally in 1978.
GBT chairman of the board Greg O’Hara said: "He brings a wealth of industry experience and expertise and will play an important role as we integrate HRG, delivering continuity and helping to provide value for all stakeholders and shareholders."
Radcliffe is also a non-executive director of Wincanton plc, the transport and logistics services provider, and a member of its Audit, Nominations and Remunerations Committees.
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