The Competition and Markets Authority (CMA) says it has given approval for online food delivery service Just Eat's £200m ($260m) takeover of rival Hungryhouse.
The CMA ruled after an in-depth investigation that the merger did not pose competition concerns given the popularity of other food delivery services such as Deliveroo, UberEats and Amazon.
"These companies generally present a greater competitive challenge to Just Eat than Hungryhouse, and this is likely to grow as they expand," the regulator said in a statement.
Both Just Eat and Hungryhouse act as intermediaries between customers and food outlets.
Just Eat, which launched in Denmark in 2001 but is now based in London, operates in 13 countries. It boasts a database of over 27,000 restaurants in the UK, while Hungryhouse covers more than 10,000 restaurants.
"The group found that Hungryhouse presently provides limited competition to Just Eat because it is much smaller in size and offers too few unique restaurants," the CMA said.
"This makes it increasingly difficult for Hungryhouse to attract and retain consumers.
"In reaching its final conclusion, the group also took account of the fact that some customers may order directly from takeaway restaurants, either by telephone, through their websites or by walking in."
Andrew Griffith, interim chairman of Just Eat, said, "The combination with Hungryhouse will enable us to bring benefits to even more independent restaurants, while improving the service and breadth of choice that we offer consumers."
"We are therefore pleased with the CMA's decision and look forward to bringing Hungryhouse into the Just Eat family."
Just Eat expects the takeover to complete by 31 January next year. Its share price rose by more than 1% on the news during early trading in London on Thursday, 16 November.
In addition to striking a deal to buy Hungryhouse, the takeaway food delivery service had earlier agreed a £66m deal to buy Canada's SkipTheDishes in December 2016.