205 ILCS 645/11
A foreign banking corporation holding a certificate of authority issued pursuant to this Act may be required, when deemed necessary and appropriate in the opinion of the Commissioner, to keep on deposit with the Federal Reserve Bank of Chicago or such State bank or national bank as such foreign banking corporation may designate and the Commissioner may approve, interest-bearing stocks and bonds, notes, debentures or other obligations of the United States or any agency or instrumentality thereof or guaranteed by the United States, or of this State, or of a city, county, town, village, school district, or instrumentality of this State or guaranteed by this State, or dollar deposits, or obligations of the International Bank for Reconstruction and Development, or obligations issued by the Inter-American Development Bank, or obligations of the Asian Development Bank, or obligations of the African Development Bank, or obligations of the International Finance Corporation, or such other assets as the Commissioner shall permit, to an aggregate amount, based upon principal amount or market value, whichever is lower, in the case of the above-described securities, and subject to such limitations as he shall prescribe such amount as the Commissioner deems necessary for the protection of depositors or the costs of taking possession and control. The deposit shall be maintained with the Federal Reserve Bank of Chicago or any such State bank or national bank pursuant to a deposit agreement in such form and containing such conditions and limitations (including a deposit in the name of the Commissioner in trust for the depositors of such banking office) as the Commissioner may prescribe. So long as it continues business in the ordinary course such banking office shall, however, be permitted to collect interest on the securities so deposited and from time to time exchange, examine and compare such securities.
205 ILCS 645/11