Blocklisting Interim Review

National Grid PLC
13 February 2006



National Grid plc ('NG')

13th February 2006

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Block Listing Six Monthly Return

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NB: References are to NG Ordinary shares of 1117/43p.
1. Name of Company                                      National Grid plc

2. Name of Scheme                                       Employee Shareschemes

3. Period                                               1 August 2005 to 31 January 2006.

4. Shares not issued at end of last period:

                                                        11,037,301 (new blocklisting, 1 August 2005)
5. Shares issued/allotted during period:                1,661,212

6. Balance not yet issued/allotted at end of period:    9,376,089

7. No. of shares originally listed and date of          On 1 August 2005, following NG's capital consolidation,
admission:                                              a total of 2,712,727,627 New Ordinary Shares of 11 17/43
                                                        pence were in issue.



Total number of shares in issue at end of the period: 2,714,388,839

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Contact: D C Forward, Assistant Secretary

Tel: [phone]


National Grid plc ('NG')

13th February 2006

-----------------------------------------------------

Block Listing Six Monthly Return

-----------------------------------------------------

NB: References are to NG Ordinary shares of 1117/43p.

1. Name of Company                                      National Grid plc

2. Name of Scheme                                       National Grid Electricity Transmission plc-
                                                        4.25 per cent Exchangeable Bonds 2008.

3. Period                                               1 August 2005 to 31 January 2006.

4. Shares not issued at end of last period:

                                                        37,388 (new blocklisting, 1 August 2005)
5. Shares issued/allotted during period:                  Nil

6. Balance not yet issued/allotted at end of period:    37,388

7. No. of shares originally listed and date of          On 1 August 2005, following NG's capital consolidation,
admission:                                              a total of 2,712,727,627 New Ordinary Shares of 11 17/43
                                                        pence were in issue.



Total number of shares in issue at end of the period: 2,714,388,839

-----------------------------------------------------------------

Contact: D C Forward, Assistant Secretary




Tel: [phone]


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