B Share Dealings

National Grid Transco PLC
20 July 2005

                                                                    20 July 2005

                           National Grid Transco plc

 Commencement of conditional dealings in B Shares on the London Stock Exchange

Following the announcement of details of the Return of Cash on 6 June 2005,
National Grid Transco plc notes that conditional dealings in B Shares will
commence tomorrow on the London Stock Exchange.

It is expected that admission to the Official List and to trading on the London
Stock Exchange's market for listed securities ('Admission') will become
effective and that unconditional dealings in the B Shares will commence on 1
August 2005. Dealings on the London Stock Exchange before Admission will only be
settled if Admission takes place. All dealings before the commencement of
unconditional dealings will be of no effect if Admission does not take place and
such dealings will be at the sole risk of the parties concerned.


Enquiries:
National Grid Transco plc
Investors

Alexandra Lewis                                             [phone]
David Campbell                                              [phone]
Richard Smith                                               [phone]


Media
Clive Hawkins                                               [phone]



JPMorgan Cazenove, Broker to National Grid Transco
Jonathan Wilcox                                             [phone]
Matthew Lawrence                                            [phone]



Citigate Dewe Rogerson, PR Advisers to National Grid Transco
Anthony Carlisle                                             [phone]


Additional Information:

In the United States, National Grid Transco plc has filed a Tender Offer
Statement on Schedule TO (the 'Schedule TO') containing the Circular to
Shareholders, a US Supplemental Memorandum, an Election Form and a Letter of
Election and Transmittal for shareholders and holders of American Depositary
Receipts, respectively, and other related documentation with the SEC. Free
copies of the Schedule TO and the other related documents filed by National Grid
Transco plc in connection with the B Share Alternatives are available on the
SEC's website at http://www.sec.gov.


                      This information is provided by RNS
            The company news service from the London Stock Exchange