A corporation that is operated privately but is backed by a branch of government and has a public mandate to provide a given service. Two examples are: the Federal National Mortgage Association (Fannie Mae), which was founded to encourage growth in the secondary mortgage market; and the Student Loan Marketing Association (Sallie Mae), which was started to encourage the growth of a secondary market for student loans. The most typical scenario is that the quasi-public corporation began as a government agency but over time has become private.