United Co-op is still on the acquisition trail, following the purchase of the 12-store Willis convenience chain. The Willis group is the sixth chain of c-stores which United Co-op has acquired in the past four years, and has an annual turnover of £7.5m. United chief executive Martin Beaumont said: "The stores are mainly located in South Yorkshire. "They will make a good fit with our existing convenience store business west of the Pennines." A United Co-op spokesman added: "We are always on the look-out for other opportunities, either chains or standalone convenience stores, off licences and newsagents. "We have the funds to do the deal if suitable opportunities present themselves," he said. Six of the 12 new Willis stores will be converted to the Late Shop format by Christmas, and the other six will be reviewed in the new year. Earlier this year United offered a bounty' for anyone notifying it of a store it later purchased, but none has been claimed so far. {{NEWS }}