A landholding agency may be the disposal agency for real and related personal property when--
(a) The agency has statutory authority to dispose of real and related personal property;
(b) The agency has delegated authority from GSA to dispose of real and related personal property; or
(c) The agency is disposing of--
(1) Leases, licenses, permits, easements, and other similar real estate interests held by agencies in non-Government-owned real property;
(2) Government-owned improvements, including fixtures, structures, and other improvements of any kind as long as the underlying land is not being disposed; or
(3) Standing timber, embedded gravel, sand, stone, and underground water, without the underlying land.