Radcliffe was appointed chief executive of HRG in 1997 and led the company’s successful repositioning as a focused corporate services group.
He was appointed to its board in 1989, having joined the group originally in 1978.
Greg O’Hara, chairman of the board at American Express Global Business Travel, said: “I will be delighted to welcome David to the GBT Board following the completion of GBT’s acquisition of HRG.
“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, the transport and logistics services provider, and a member of its audit, nominations and remunerations Committees.
Radcliffe said: “I’m excited to be given the opportunity to join the Board of the combined group following the completion of GBT’s acquisition of HRG and to work with the best talent and technology from both organisations.
“The transaction will create a truly world-class company capable of delivering significant benefits to clients, colleagues and suppliers.”