RNS Number:1995P
Marconi Corporation PLC
29 August 2003


                                                               Aviva plc
                                                               PO Box 89
                                                               Surrey Street
                                                               Norwich NR1 3DR



The Company Secretary
Marconi Corporation plc
4th Floor
Regents Place
338 Euston Road
London NW1 3BT


Dear Sir


MARCONI CORPORATION PLC (THE "COMPANY") - SEDOL 3280069

This notification supersedes our previous notification to you dated 18 July 2003
and is prompted by purchases totalling 3,790,000 on 28 August 2003.

This notification relates to issued ordinary shares of 5p each in the capital of
the Company (the "shares") and is given in fulfilment of the obligations imposed
by sections 198 to 202 of the Companies Act 1985 (the "Act").
     
1.   Notification on behalf of Morley Fund Management Limited (a subsidiary of 
     Aviva plc).
     
1.1  We hereby notify you on behalf of Morley Fund Management Limited that 
     immediately after the time when the obligation to make this notification 
     arose Morley Fund Management Limited were interested in 43,227,533 shares.
     
1.2  The identity of the registered holders of the shares to which this 
     notification relates and the number of shares held by each of them are set 
     out in the attached Appendix : Morley Fund Management Limited.
     
2.   Notification on behalf of Aviva plc.
     
2.1  We hereby notify you on behalf of Aviva plc that immediately after the time 
     when the obligation to make this notification arose Aviva plc were 
     interested in 43,227,533 shares giving the Aviva group a total percentage
     interest in the shares of 4.32%.
     
2.2  The identity of the registered holders of the shares to which this 
     notification relates and the number of shares held by each of them are set
     out in the attached Appendix: Aviva plc.

If you require further information as to which companies in the Aviva group hold
interests in the shares (by virtue of s.203 of the Act) please submit a written
request and we will be happy to supply this information.

We are only required to notify interests which are defined as material interests
when the holding is equal to 3% or more of the Company's relevant share capital.
The term material interests exclude certain categories where we do not hold a
beneficial interest, for example where the shares are held in an Authorised Unit
Trust Scheme or Open Ended Investment Company.  Holdings in those categories are
therefore not included in the holding notified under this letter.  If you wish
us to confirm the level of holdings in these categories, please let us know.


Yours faithfully


Margaret Watts
For and on behalf of
Aviva plc



The Company Secretary                                             29 August 2003
Marconi Corporation plc


APPENDIX: MORLEY FUND MANAGEMENT LIMITED

REGISTERED HOLDERS                                 NUMBER OF SHARES HELD

BNY Norwich Union Nominees Ltd                     15,551,986 (Material)
Chase GA Group Nominees Ltd                        17,420,128 (Material)
CUIM Nominees Ltd                                  10,255,419 (Material)


TOTAL PERCENTAGE INTEREST OF MORLEY FUND MANAGEMENT LIMITED: 4.32%
ISSUED SHARE CAPITAL ON WHICH THIS NOTIFICATION IS BASED: 1,000,000,000


The Company Secretary                                             29 August 2003
Marconi Corporation plc


APPENDIX: AVIVA PLC

REGISTERED HOLDERS                                 NUMBER OF SHARES HELD

BNY Norwich Union Nominees Ltd                     15,551,986 (Material)
Chase GA Group Nominees Ltd                        17,420,128 (Material)
CUIM Nominees Ltd                                  10,255,419 (Material)


TOTAL PERCENTAGE INTEREST OF AVIVA PLC: 4.32%
ISSUED SHARE CAPITAL ON WHICH THIS NOTIFICATION IS BASED: 1,000,000,000



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