Walmart de Mexico, or Walmex, said it has always acted in accordance with applicable law and that its participation in the Mexican market has resulted in lower prices for consumers, benefiting poor families especially.
The federal competition authority Cofece said it could not comment on Walmart's statement.
In a Nov. 4 study, Cofece said there was a need to facilitate the entry of more competitors to the retail market.
"High market concentration favors the purchasing power of large self-service chains compared to their smaller suppliers, which could distort competition in supplier markets," the Cofece study said.
In the study, Cofece identified Walmart and Soriana, and to a lesser degree Chedraui, as the main players with a national presence.
(Reporting by Adriana Barrera; Additional reporting by Daina Beth Solomon; Writing by Anthony Esposito; Editing by Frank Jack Daniel)