There are 37 food retail co-operative societies, the largest being the Co-operative Group, followed by United Co-operatives and Midlands Co-op.
The modern co-operative movement began in 1844 in Rochdale, Lancashire, when 28 workers set up a co-operatively owned and run shop that would treat customers fairly and trade honestly, which explains the continuing strong emphasis on ethics and community involvement today.
Co-operatives are not companies but societies composed of members who own them and democratically control what they do.
Customers can become members by investing in them. Members enjoy an equal share of some of their profits, usually through discount schemes or dividends. They can also choose to donate some of this dividend to community causes.
Recently the Co-operative Group announced plans to reintroduce its famous dividend scheme in 2005.
Co-ops can raise money to invest in business ventures in much the same ways as publicly limited companies, except that they are unable to issue shares.
Cash is mainly generated through a mixture of retained profits and borrowings from banks and capital markets.
Bonds can also be used as an alternative. In the last year, for example, the Co-op Group has raised £200m by issuing Eurobonds via UBS.