The Co-op is to offload nearly 300 of its smaller stores to rival grocery and newsagent brand McColls.
Workers have been assured there will be no job losses for the 3,808 staff working in 298 branches affected by the sale.
Staff have been told they will also keep the same job terms and conditions.
The Co-op sold one of its largest Salford stores, in Irlams o’th Height, to Aldi in 2014.
The stores targeted for sale are those less than 1,700sq ft.
Co-op wants to increase sales of its own-brand products and said the stores up for sale were too small to stock these types of goods.
The £117m buy-out will have to be agreed by the Competition and Markets Authority before it can go ahead.
Co-op Food chief executive Steve Murells said: “Today’s announcement is completely in line with our strategy, as these stores did not allow us to provide a sufficiently compelling own-brand offer for our members going forwards.”
“The proceeds will be re-invested to drive sustainable growth for our members and I’m delighted that all 3,808 colleagues will transfer to McColl’s on the same terms and conditions,” he added.
Usdaw, the UK’s fourth biggest trade union, says it has been assured there will be no redundancies in the sale.
John Gorle, Usdaw National Officer, said that whenever a deal like this is proposed with a transfer of staff there is always uncertainty about the future.
“We welcome the Co-op’s assurances that terms and conditions of employment will be safeguarded and staff will continue to have secure jobs with a future,” he said.
The outlets involved in the transfer will continue to trade under the Co-op name until November 2016.
