The Office of Fair Trading has referred Booker’s £140m acquisition of Makro Cash & Carry to the Competition Commission.

The OFT said that the deal, first announced in May this year, “raised competition concerns at a national level”. There were further concerns in 13 local areas where Booker and Makro both have depots.

“We are concerned that the loss of rivalry due to the merger may result in higher prices or a reduction in service to both retailers and caterers, and ultimately to consumers,” said OFT chief economist and decision maker Amelia Fletcher.

“Although the parties did offer to divest some outlets to address some local area concerns, it was not sufficient to remove our competition concerns at the national level or indeed all of the local areas in which we have concerns. We are therefore referring the merger for a fuller investigation to the Competition Commission.”

Booker unveiled detailed plans for the Makro business last month, which included making the most of Makro’s large depots by introducing delivery areas and Booker concessions into sites.

“Booker looks forward to working with the Competition Commission through the inquiry. Makro UK will continue to be held separate from the rest of Booker until the inquiry is complete,” Booker said in a statement.