Plymouth & South West Co-op said turnover rose 5.2% to £154m in the year to 24 January. Trading profits at the business, which has 69 food stores in Devon and Cornwall and has proposed a merger with The Co-operative Group, rose 69% to £6.4m.
Its food division had its "best year ever" thanks to an ongoing refurbishment programme and improved product range, said CEO Douglas Fletcher.
"The society is in a fantastic financial position despite the turbulent market conditions and the deepening of the recession," he added.
Plymouth & South West Co-op members are expected to vote on the merger in a series of meetings next week.
Heart of England Co-op, which has 33 food stores across Coventry and Warwickshire, reported a 4% increase in sales to £81m and a 6% increase in trading profits to £4.2m. Like-for-like sales in its food division rose 8.6%, boosted by store refurbishments.
"Everywhere has been hit hard since the start of the downturn and the society is no exception to the current economic climate," said CEO Ali Kurji.
"However, policies we've had in place in recent years are allowing us to continue to build a strong regional co-operative business."