§ 111. Mortgages and mortgage bonds. Any redevelopment company, subject to the approval of the supervising agency, may borrow funds and secure the repayment thereof by bond and mortgage or by an issue of bonds under a trust indenture. Each mortgage or issue of bonds of a redevelopment company shall relate only to a single specified project and to no other and such bonds shall be secured by mortgage upon all of the real property of which such project consists. First lien bonds of such redevelopment company when secured by a mortgage not exceeding ninety per centum of the estimated cost prior to the completion of the project, and in no event exceeding ninety per centum of the actual cost upon such completion, as certified by the supervising agency, or, in the case of a completed project, not exceeding ninety per centum of the appraised value or such previously certified actual cost, whichever is less, are hereby declared securities in which all public officers and bodies of the state and of its municipal subdivisions, all insurance companies and associations, all savings banks and savings institutions, including savings and loan associations, executors, administrators, guardians, trustees and all other fiduciaries in the state may properly and legally invest the funds within their control. First lien bonds of such a redevelopment company issued under a trust indenture and pursuant to a building loan contract, or a building loan bond and building loan mortgage under which advances are made pursuant to a building loan contract, where the aggregate principal amount to be issued or advanced does not exceed ninety per centum of the estimated cost prior to the completion of the project, and in any event does not exceed ninety per centum of the actual cost upon such completion, as certified by the supervising agency, are hereby declared securities in which all banks, savings banks, savings institutions and trust companies in addition to all such officers, bodies, companies, associations, institutions and fiduciaries may properly and legally invest the funds within their control; provided, however, that such investment is made as a construction loan with a maturity of not to exceed two years. The maturity of any such construction loan may be extended from time to time with the approval of the board of directors or trustees of the bank, savings banks, savings institutions or trust company holding such loan but no one such extension shall be for a period of time exceeding six months. The bonds so issued and secured and the mortgage or trust indenture relating thereto, may create a first or senior lien and a secondary or junior liens upon the real property embraced in any project; provided, however, that the total mortgage liens shall not exceed ninety per centum of the estimated cost prior to the completion of the project, and shall not in any event exceed ninety per centum of the actual cost upon such completion, or, in the case of a completed project, not exceeding ninety per centum of the appraised value or such previously certified actual cost, whichever is less. Such bonds and mortgages or trust indentures may contain such other clauses and provisions as shall be approved by the supervising agency, including the right to assignment of rents and entry into possession in case of default and including in the case of a redevelopment company which is a partnership or trust the right of the partners or trustees, as the case may be, to be free of any personal liability thereunder; but the operation of the housing project in the event of such entry by mortgagee or receiver shall be subject to regulations promulgated by the supervising agency. Provisions for the amortization of the bonded indebtedness of companies formed under this article shall be subject to the approval of the supervising agency. So long as funds made available by the federal government or any instrumentality thereof or any mortgage or mortgage bonds, insured by the federal housing administrator or any other instrumentality of the federal government are used in financing, in whole or in part, any project under this article, the capital structure of a redevelopment company undertaking such project and the proportionate amount of the cost of the lands and improvements to be represented by mortgages or bonds shall be entirely in the discretion of the supervising agency; and all restrictions as to the maturity of any construction loan and as to the amounts to be represented by mortgages, mortgage bonds, income debentures or capital shall be inapplicable to such projects or to redevelopment companies undertaking such projects, except that the bonds, mortgages, debentures and capital covering any project shall not exceed the total actual final cost of such project as defined in subdivision two of section one hundred twelve of this article. Interest rates on mortgage indebtedness shall not exceed the greater of

(a) six percentum per annum,

(b) the rate prescribed by the superintendent of financial services pursuant to section fourteen-a of the banking law,

(c) the rates of mortgages or mortgage bonds insured by the federal housing administration or any other instrumentality of the federal government and

(d) such rate as may be approved by the supervising agency provided, however, that the applicable rate for purposes of paragraphs (b), (c) and (d), of this section one hundred eleven shall be the rate applicable or approved at the time the redevelopment company incurs the mortgage indebtedness. As used in this section the term "bond" includes a note heretofore or hereafter made.