20 ILCS 3515/17

The State and all counties, cities, villages, incorporated towns, and other municipal corporations, political subdivisions and public bodies, and public officers of any thereof, all banks, bankers, trust companies, savings banks and institutions, building and loan associations, savings and loan associations, investment companies, insurance companies and associations, and all executors, administrators, guardians, trustees and other fiduciaries may legally invest any sinking funds, monies or other funds belonging to them or within their control in any bonds issued pursuant to this Act. No lessee from the State authority may purchase bonds of the State authority.