The Office of Fair Trading (OFT) is to investigate Thomas Cook's plans to merge its travel retail businesses with the Co-operative Group and Midlands Co-operative.
On 6 January, the European Commission told Thomas Cook that it had agreed to the OFT's request to have sole jurisdiction over the proposals as it related to the UK only.
A statement from Thomas Cook said: "We will continue to work closely with the OFT to obtain a rapid clearance."