A lender may sell loans guaranteed by the corporation, or an interest in such loans, to another lender only in accordance with regulations of the corporation; and in such event the guaranty liability of the corporation on such loans or interests therein shall not be affected. A lender may pledge or assign loans guaranteed by the corporation, or an interest in such loans, as security to pledgees or assignees only in accordance with regulations of the corporation; and in such event the guaranty liability of the corporation on such loans or interests therein shall not be affected.