The latest acquisitions come from the Essex-based retail group Wisebuys. The group paid an undisclosed seven-figure sum for the outlets in Blackmore, Hutton and Great Notley.
The buyout of the three Wisebuys outlets takes the total number of stores purchased by the Chelmsford Star Co-operative Society over the past three months to five.
The total number of stores in its estate now stands at 33.
Chelmsford Star Co-operative Society deputy chief executive officer Barry Wood said the acquisitions would enable it to bring the Co-operative brand to places where it had been missing in recent years.
"We look forward to the Co-operative successfully trading in these areas for years to come," he added.
The three stores would be re-branded under the society's new corporate signage in the next few weeks, he said.
Wisebuys continues to operate a further two Nisa-branded stores in Essex, in Ongar and Brentwood.