Launched on 22 February, the first phase of the inquiry is an invitation to comment, which will be open until 9 March 2018.
The regulator is examining whether the transaction, if carried into effect, would result in the creation of a relevant merger situation which might cause “substantial lessening” of competition within the markets. The CMA will take a decision by 23 April.
Nisa members approved the Co-op Group’s offer to buy the business for £137.5m in November last year but the offer requires the approval of CMA.
Nisa is a brand and buying group of independent retailers and wholesalers in the UK.
The Group became the exclusive bidder for Nisa after Sainsbury’s dropped out, arguably due to concerns that CMA could block the acquisition.
Also a mutual, Nisa includes members who own convenience stores, with their stake being based on how many stores they own. It provides a franchise model for 3,466 convenience stores owned by 1,300 members. At the time the deal was reached, Nisa chair Peter Hartley said the Group would add buying power and product range to the mutual’s offering, while respecting its culture of independence. The Group would also take on Nisa’s existing debt of £105m.
Last year Nisa reported annual sales totalling £728m for the 26 weeks to October 2017, up by 12.4% from the previous year.
A spokesman for the Group said: “We’re in a process where CMA is reviewing the deal and we’re waiting to hear the outcome, so we’re limited in what we can say at present. We remain grateful for the patience of all the retailers who are also waiting to hear if the deal is approved.”