The Competition and Markets Authority (CMA) will examine whether the deal results in a substantial lessening of competition.

Earlier this month, Morrisons, which has a wholesale supply deal with McColl's, took on all its 1,160 stores, including 270 Morrisons Daily branded stores, in a so-called pre-pack administration.

Morrisons, which trails market leader Tesco, Sainsbury's and Asda, has been owned since October by U.S. private equity group Clayton, Dubilier & Rice (CD&R).

(Reporting by James Davey; editing by Jason Neely)