to carry out, the local authority may, by notice in writing served on the owner before any agreement as contemplated by subsection (4) is reached inform the owner that it intends requesting the Administrator to direct in terms of paragraph (c) that such portion shall be transferred to it. (b) The local authority and the owner shall thereafter determine the value immediately prior to the fixed date of the portion of land contemplated by paragraph (a) in accordance with the provisions of subsections (4), (5) and (6) and for the purposes thereof—

(i) any reference in the said subsections to the estimated difference shall be deemed to be a reference to the value of such portion;

(ii) the provisions of the said subsection (6) shall apply as if the determination of such value related to the payment of compensation, and

(iii) the period contemplated by subsection (5) (a) shall be deemed to have commenced on the date on which the notice referred to in paragraph (a) is given.

(c) The local authority shall notify the Administrator in writing of the value determined in accordance with the preceding provisions of this subsection and the Administrator may direct that, if the value so determined is equal to or less than the amount of the enhancement levy due in respect of the land concerned, the portion referred to in paragraph (a) shall be transferred to the local authority and upon the transfer of such portion to the local authority, the value so determined shall be deemed to be an amount paid in full or partial settlement, as the case may be, of such enhancement levy. (d) A due adjustment in respect of any amount paid in respect of the enhancement levy concerned shall be made upon the transfer to the local authority of the portion of land contemplated by paragraph (a). (10) (a) The Administrator may, either generally or in relation to the area of jurisdiction of any local authority, determine that the provisions of subsection (1) shall not apply in respect of any class or type of provision which may be prescribed in terms of section 35bis and any determination made in terms of this paragraph may—

(i) be made with retrospective effect to a date not earlier than the twenty-sixth day of September, 1969, and

(ii) at any time be altered or withdrawn by him.

(b) The Administrator may, on the written application of the local authority or the owner and if he is of opinion, after consultation with the local authority and the owner, that special circumstances justifying such action exist, determine that, whether or not the estimated difference has been determined in terms of this section—

(i) the provisions of subsection (1) shall not apply or be deemed not to have applied in respect of the land concerned;

(ii) in the case of an enhancement levy, the percentage contemplated by subsection (2) shall be reduced or be deemed to have been reduced to a percentage specified by him, or

(iii) in the case of compensation, only such proportion of the estimated difference as he may direct shall be due or be deemed to have been due to such owner,

and in such event a due adjustment shall be made in respect of any amount paid prior to such determination as an enhancement levy or compensation and any amount deemed, in terms of subsection (9), to have been paid in full or partial settlement of an enhancement levy.