The UK’s Competition and Markets Authority (CMA) has announced that it is investigating American Express Global Business Travel’s proposed acquisition of rival travel management company CWT.

Amex GBT’s $570 million deal to purchase CWT was first announced in March and would bring together the first and third largest TMCs in Europe. But the transaction will have to receive regulatory approval in key markets such as the US, UK and the EU.

The CMA said in a statement that it was considering whether the blockbuster TMC deal would fall “under the merger provisions of the Enterprise Act 2002” as part of its preliminary Phase 1 investigation.

“And, if so, whether the creation of that situation may be expected to result in a substantial lessening of competition within any market or markets in the United Kingdom for goods or services,” added the CMA.

The authority is inviting comments on the impact of the Amex GBT-CWT deal “from any interested party”, with a deadline for submissions of 18 June.

The CMA has also set the deadline of 30 July to decide whether to give the acquisition the green light or go ahead with a more in-depth Phase 2 investigation.

Amex GBT has previously said that it hoped to complete the purchase of CWT during the second half of this year. 

For more background about this deal, read BTN Europe’s interview with Amex GBT’s CEO Paul Abbott about the company’s rationale for buying CWT.