American Express Global Business Travel expects to seal the takeover of Hogg Robinson Group this week.
The acquisition, valuing HRG at up to £410 million, is due to be completed on Thursday after GBT won merger control clearance from the European Union.
The transaction was previously cleared by regulators in Russia and the US but had been pushed back awaiting EU approval.
GBT claims to be the world’s leading business partner for managed travel with 12,000 staff in 140 countries while HRG is a global B2B services company specialising in travel management.
“The combined group is expected to offer clients and travellers a wider range of products and services, bringing together the best of both businesses including technology, people and a comprehensive geographic footprint,” GBT said.