The concessioner may not assign, sell, convey, grant, contract for, or otherwise transfer (such transactions collectively referred to as “assignments” for purposes of this part), without the prior written approval of the Director, any of the following:

(a) Any concession contract;

(b) Any rights to operate under or manage the performance of a concession contract as a subconcessioner or otherwise;

(c) Any controlling interest in a concessioner or concession contract; or

(d) Any leasehold surrender interest or possessory interest obtained under a concession contract.