(a) All property of an urban renewal agency, including funds, owned or held by it for the purposes of this act shall be exempt from levy and sale by virtue of an execution, and no execution or other judicial process shall issue against the same nor shall judgment against an agency be a charge or lien upon such property: Provided, however, that the provisions of this section shall not apply to or limit the right of obligees to pursue any remedies for the enforcement of and pledge or lien given pursuant to this act by an agency on its rents, fees, grants or revenues from urban renewal projects.
(b)  The property of an urban renewal agency, acquired or held for the purposes of this act, is declared to be public property used for essential public and governmental purposes and effective the date an urban renewal agency acquires title to such property it shall be exempt from all taxes of the municipality, the county, the state or any political subdivision thereof: Provided, that such tax exemption shall terminate when the agency sells, leases or otherwise disposes of such property in an urban renewal area for redevelopment to a purchaser or lessee which is not a public body entitled to tax exemption with respect to such property.