LONDON (AP) — British regulators have opened an initial investigation into a merger between U.K.-based food delivery company Just Eat and its Dutch rival Takeaway.com over worries that it might stifle competition.

The Competition and Markets Authority said Friday it's looking into whether the 6 billion-pound ($8 billion) deal will "result in a substantial lessening of competition" in the U.K. market.

Just Eat shareholders accepted Takeaway.com's bid this month, in a deal to form one of the biggest players in the fiercely competitive food delivery market. Takeaway.com indicated the deal would still proceed but would be delayed by a week, with shares in the renamed Just Eat Takeaway.com now expected to start trading on Feb. 3.

The Dutch company pulled out of Britain in 2016. It said the regulator would be examining whether it would have re-entered the U.K. market without the Just Eat deal.

Takeaway.com said it “is confident that merger clearance will be obtained.”