The Principal Act is amended in Part 29 by the insertion after Chapter 3 of the following:

"Chapter 4 Transmission Capacity Rights

769A. Interpretation (Chapter 4).

(1) In this Chapter -

'capacity rights' means the right to use wired, radio or optical transmission paths for the transfer of voice, data or information:

'writing-down period' has the meaning assigned to it by section 769B(2).

(2) In this Chapter, any reference to the sale of part of capacity rights includes a reference to the grant of a licence in respect of the capacity rights in question, and any reference to the purchase of capacity rights includes a reference to the acquisition of a licence in respect of capacity rights; but, if a licence granted by a company entitled to any capacity rights is a licence to exercise those rights to the exclusion of the grantor and all other persons for the whole of the remainder of the term for which the rights subsist, the grantor shall be treated for the purposes of this Chapter as thereby selling the whole of the rights.

769B. Annual allowances for capital expenditure on purchase of capacity rights.

(1) Where, on or after 1 April 2000, a company incurs capital expenditure on the purchase of capacity rights, there shall, subject to and in accordance with this Chapter, be made to that company writing-down allowances, in respect of that expenditure during the writing-down period; but no writing-down allowance shall be made to a company in respect of any expenditure unless -