Preservation of equity of state in lands sold; board of trustees may compromise unpaid balance.

In the sale of state lands or other state property, whether made in the name of the state or in the name of any state agency, when such sale is or has been made upon the basis of partial payment or payments upon said lands or other property and the remainder or balance of payment or payments is or was secured by note or notes, in turn secured by mortgage or mortgages, or other paper or instrument obligating the lands or property, or any part thereof, to the payment of any remaining or balance of payment or payments, the equity and interest of the state or any state agency making such sale as represented by said notes, mortgages, or other such instruments, shall never be extinguished, canceled or impaired so long as the obligation to the state or state agency shall remain unpaid or unfulfilled; provided, the Board of Trustees of the Internal Improvement Trust Fund may, in its discretion, compromise, or compound, any unpaid balance on any contract to purchase any lands over which said board of trustees has jurisdiction and control, where such contract to purchase is secured by a mortgage, if no less than 25 percent of the agreed purchase price has been theretofore paid.