The sector made a combined pre-tax profit of £539m in 2007 and 10.8 million people - about a fifth of the UK population - had a share in businesses run by co-operatives, Co-operatives UK has reviewed in its annual review.
The Co-operative Group also topped Co-operative UK's rankings of the UK's 100 largest co-ops by turnover for the 2006-07 financial year.
It beat John Lewis Partnership - the parent company of Waitrose - Midlands and Midcounties co-ops and Dairy Farmers of Britain.
"Many people underestimate the contribution that co-operatives make to the UK economy but, as these figures show, they are a real force in job creation, social change and the delivery of important services in this country," said Co-operatives UK chief executive Dame Pauline Green.
"In recent years, UK co-operatives have experienced something of a renaissance. The merger of the Co-operative Group and United Co-operatives in July 2007 created the world's largest consumer co-operative and the John Lewis Partnership has continued to outperform the market in times of economic uncertainty."
In a separate survey, The Co-operative Group - which is currently closing a deal to buy Somerfield - also topped a list of Co-operative UK's 22 members by turnover with sales of £9.1bn last year.
Midlands Co-op was a distant second in the rankings, with turnover of £853m, ahead of Midcounties Co-op, East of England Co-op and Scottish Midland Co-op in fifth.
The Co-operative Group said it is currently on track to rebrand 700 food stores this year, refurbishing 15 outlets a week.
A spokeswoman said that the programme would be complete by the end of 2009.