RNS Number:5229U
Marconi Corporation PLC
22 January 2004

The company received the following notification yesterday:


    Aviva plc
    P O Box 89
    Surrey Street
    Norwich NR1 3DR



The Company Secretary
Marconi Corporation plc
34 Grosvenor Square
LONDON W1K 2HD


    21 January 2004



Dear Sir,



MARCONI CORPORATION PLC (THE "COMPANY") - SEDOL 3335442



This notification supersedes our previous notification to you dated 22 September
2003 and is prompted by sales totalling 602,160 on 20 January 2004.



This notification relates to issued ordinary shares of 25p 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 11,745,254
shares.



1.2              The identification 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 11,745,254 shares giving the Aviva group a total percentage
interest in the shares of 5.86%.



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


Abby Condick
For an on behalf of
Aviva plc



The Company Secretary                                            21 January 2004
Marconi Corporation plc


APPENDIX: MORLEY FUND MANAGEMENT LIMITED

REGISTERED HOLDERS                                         NUMBER OF SHARES HELD

BNY Norwich Union Nominees Ltd                            2,810,270   (Material)

Chase GA Group Nominees Ltd                            5,659,755      (Material)

CUIM Nominee Ltd                                       3,275,229      (Material)


TOTAL PERCENTAGE INTEREST OF MORLEY FUND MANAGEMENT LIMITED: 5.86%

ISSUED SHARE CAPITAL ON WHICH THIS NOTIFICATION IS BASED: 200,400,000





The Company Secretary                                            21 January 2004
Marconi Corporation plc



APPENDIX: AVIVA PLC

REGISTERED HOLDERS                                         NUMBER OF SHARES HELD

BNY Norwich Union Nominees Ltd                             2,810,270  (Material)

Chase GA Group Nominees Ltd                                5,659,755  (Material)

CUIM Nominee Ltd                                          3,275,229   (Material)

Ohra Belgium Non-Life                                          1      (Material)

TOTAL PERCENTAGE INTEREST OF AVIVA PLC: 5.86%

ISSUED SHARE CAPITAL ON WHICH THIS NOTIFICATION IS BASED: 200,400,000




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