Dave's, which has off-licences, Post Offices and convenience stores in the Midlands, snapped up 41 stores in the 56-store chain.
Three stores have been returned to landlords by Midcounties, while a further 12 have been retained and will be converted into Co-op stores. Dave's said the deal would complement its existing portfolio and that it remained on the lookout for more sites.
Midcounties bought News Express in January 2007 from publisher Claverley Company. Under Claverley's ownership it had 150 stores and traded as Stars News Shops. Midcounties converted a number of stores to The Co-operative fascia, and operated 56 under the News Express fascia.
"The decision has been taken following a thorough review of the Midcounties business and the sectors in which we wish to trade," said a spokesman. "All colleagues affected will be transferred to the new owner under TUPE legislation. We expect the transfer to take place by the end of September."