source exceed one-half of such excess of the net cost of the project as determined by the commissioner, the state grant or advance-in-aid for urban renewal or redevelopment shall be reduced by an equal amount. In determining the net cost of a project, nothing shall prevent the commissioner from including costs in excess of the original projected costs of such project, provided such excess cost has been approved by the United States Department of Housing and Urban Development. Contracts for state financial assistance for urban renewal or redevelopment projects executed under the provisions of this chapter prior to July 1, 1967, or contracts executed subsequent thereto for which reservations of state funds were approved by the Connecticut Development Commission prior to July 1, 1967, may be amended or executed under the provisions of this chapter and administrative procedures established hereunder, provided, if such amendment is for the purpose of providing additional state financial assistance due to an increase in the net cost of the project, as determined by the commissioner, such additional state financial assistance shall be made available from funds previously authorized for redevelopment or urban renewal programs or authorized for the purposes of this chapter and chapter 133.