The company has more than 18,000 staff in 140 countries, with 2,200 based on the UK.
A statement explained: “GBT is in a very strong financial position, but in the current environment we have to reset our cost base to more closely align with demand.
“We have taken measures to protect as many jobs as possible, including the use of government support schemes where available, voluntary retirement and voluntary severance programmes, and introducing new flexible working options.
“There are some areas where unfortunately these measures alone are insufficient.
“Only in these specific circumstances, we will consult with our colleagues on the difficult decision to implement involuntary reductions.
“We continue to consult with and support affected colleagues throughout this period.”
Reports suggest a third of the UK workforce could go, but no firm details were forthcoming from the company.
Last year, Amex GBT reported business travel gross sales of $3 billion for the UK, a figure buoyed by its merger with Hogg Robinson Group.