The Competition and Markets Authority (CMA) said it had until March 14 to make its phase 1 decision on whether the deal will reduce competition in the UK.
Asda is planning to open 300 convenience stores by the end of 2026, aiming to become a player in the smaller shop market to help drive growth, and creating thousands of new jobs in the process.
The supermarket group had agreed to buy Arthur Foodstores Ltd, which comprises of 129 sites, from Co-Operative for 600 million pounds ($736.62 million) in August last year.
Asda and Co-Operative did not immediately respond to Reuters requests for comment.
($1 = 0.8145 pounds)
(Reporting by Muhammed Husain in Bengaluru; Editing by Shailesh Kuber)
