Supermarket Tesco's £3.7 billion takeover of wholesale group Booker has been given the final all-clear after the competition watchdog said it would not lead to higher prices or hit service for shoppers.
The Competition and Markets Authority (CMA) said its in-depth investigation into the tie-up found it did not raise competition concerns despite fears raised by rival wholesalers.
The CMA said Tesco and Booker do not compete "head-to-head" in most areas in which they operate, in particular the catering sector, where Booker makes more than 30% of its sales.
It added that it "carefully" considered the impact on competition on shops supplied by Tesco - such as Premier, Londis and Budgens - that it also competes with, but found the supermarket cannot have any direct influence.
Simon Polito, chair of the CMA's inquiry group, said: "We have carefully listened to feedback from retailers and wholesalers who operate in what are highly competitive UK retail and wholesale sectors.
"Retailers have told us that they shop around for the best prices and service from their wholesaler, and we are confident that this will continue after Tesco buys Booker."
He added it had been an "important investigation".
"Millions of people use their local supermarket or convenience store to buy their groceries or essentials, so it is vital that they have enough choice to secure the best deal for them. Having examined the evidence in depth, we are satisfied this will remain the case following the merger," he said.
Tesco and Booker welcomed the decision and said the deal is now expected to complete next March.