40 ILCS 5/15-167
To invest money. To invest the funds of the system, subject to the requirements and restrictions set forth in Sections 1A-108.5, 1-109, 1-109.1, 1-109.2, 1-110, 1-111, 1-114, 1-115, and 15-158.2(d) of this Code and to invest in real estate acquired by purchase, gift, condemnation or otherwise, and any office building or buildings existing or to be constructed thereon, including any additions thereto or expansions thereof, for the use of the system. The board may lease surplus space in any of the buildings and use rental proceeds for operation, maintenance, improving, expanding and furnishing of the buildings or for any other lawful system purpose.
No bank or savings and loan association shall receive investment funds as permitted by this Section, unless it has complied with the requirements established pursuant to Section 6 of "An Act relating to certain investments of public funds by public agencies", approved July 23, 1943, as now or hereafter amended. The limitations set forth in such Section 6 shall be applicable only at the time of investment and shall not require the liquidation of any investment at any time.
The board shall have the authority to enter into such agreements and to execute such documents as it determines to be necessary to complete any investment transaction.
All investments shall be clearly held and accounted for to indicate ownership by the board. The board may direct the registration of securities in its own name or in the name of a nominee created for the express purpose of registration of securities by a national or state bank or trust company authorized to conduct a trust business in the State of Illinois.
Investments shall be carried at cost or at a value determined in accordance with generally accepted accounting principles and accounting procedures approved by the Board.
All additions to assets from income, interest, and dividends from investments shall be used to pay benefits, operating and administrative expenses of the system, debt service, including any redemption premium, on any bonds issued by the board, expenses incurred or deposits required in connection with such bonds, and such other costs as may be provided in accordance with this Article.
40 ILCS 5/15-167