Holding(s) in Company

RNS Number:3564U
Marconi Corporation PLC
16 January 2004


The company today received the following notification:

                                                                 Legal & General
                                                   Investment Management Limited
                                                              Bucklersbury House
                                                         3 Queen Victoria Street
                                                                 London EC4N 8NH

16 January, 2004


Marconi Corporation
34 Grosvenor Square
London
W1A 4QP
Attn:  Company Secretary



DISCLOSURE OF INTEREST IN SHARES UNDER SECTION 198

Consequent upon a transfer into management of 103,623 shares on the 14 January
2004, Legal & General Group Plc companies are now the beneficial owners of the
following number of shares which are not subject to a concert party and will be
registered as follows:

Material Interest

HSBC Global Custody Nominee (UK) Ltd A/C 914945        73,000
HSBC Global Custody Nominee (UK) Ltd A/C 775245       847,253
HSBC Global Custody Nominee (UK) Ltd A/C 357206     4,601,925
HSBC Global Custody Nominee (UK) Ltd A/C 866203       281,000
HSBC Global Custody Nominee (UK) Ltd A/C360509        249,779
                                                    6,052,957             3.02%



Please note that this percentage is based on our understanding that your issued
share capital is 200,400,000, which is the figure quoted by Exshare.

Please address any queries you may have to Julia Stone on 020 7528 6742.



Yours faithfully,

Julia Stone                                          Lee Toms
Authorised Signatory                                 Authorised Signatory


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

HOLBFMPTMMMBBRI