Trade and marketing manager John Liptrot said the group was signing up its first retailers at CRS.
Key Lekkerland needed to get 100 on board before the service became viable to launch, he said.
The 24-hour radio station will play easy listening music interspersed with adverts from suppliers and special promotions.
The "Key radio" branded service would be exclusive to KeyStores, said Liptrot. The service costs £1 a day for a three-year contract. Key Lekkerland will provide the retailer with equipment.