In a provisional findings report, published today, the commission concluded that the acquisition of the store in 2003 had resulted in a “substantial lessening of competition” in the grocery market in Slough.
The Office of Fair Trading originally referred the case to the commission in February 2004, because it was concerned that the new store would have an overlapping catchment area with another Tesco store.
Tesco was ordered to stop developing on the site last month while the commission looked into the case.
Peter Freeman, inquiry group chairman said: “We will now look to discuss what action we can take with regard to the Co-op site and restoring competition. As Tesco originally bought the Co-op store nearly four years ago, the circumstances surrounding this case are unusual both in terms of a merger inquiry and also its relevance for the ongoing market grocery investigation.”