The board of supervisors may convey any land and improvements thereon owned by the county directly and without compliance with the provisions of paragraph 9 of section 11-251 to a nonprofit corporation which operates housing units limited to those which are federally financed or sponsored. Such title so conveyed shall remain with the nonprofit corporation until such time as the bonded indebtedness incurred and due to the United States government or an agency thereof, is paid and at which time title to such land and the improvements thereon shall revert to the county.