Blocklisting Interim Review

National Grid PLC
07 August 2006



National Grid plc ('NG')

7th August 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 February 2006 to 31 July 2006

4. Shares not issued at end of last period:             9,376,089

5. Shares issued/allotted during period:                6,425,301

6. Balance not yet issued/allotted at end of period:    2,950,788

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:  2,720,814,140

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Contact: D C Forward, Assistant Secretary

Tel: [phone]


National Grid plc ('NG')

7th August 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 February 2006 to 31 July 2006.

4. Shares not issued at end of last period:             37,388

                                                        
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: 2,720,814,140

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

Contact: D C Forward, Assistant Secretary

Tel: [phone]


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