Re Agreement

RNS Number:1055U
Marconi Corporation PLC
12 January 2004


                                                                Press enquiries:
                   Joe Kelly tel: [phone]; email: [e-mail]
                 David Beck tel: [phone]; email: [e-mail]

                                                             Investor enquiries:
                                    Heather Green tel: + 44 207 306 1735; email:
                                                       [e-mail]

   MARCONI CORPORATION SUPPLIES TELIASONERA WITH NEW FLEXIBLE NEXT GENERATION
                                NETWORK PLATFORM

          Scandinavian Carrier Looks to Reduce Capex and Opex by using
                          Marconi's latest technology

London - 12th January, 2004 - Marconi Corporation (London: MONI and Nasdaq:
MRCIY) today announced that TeliaSonera, the leading Scandinavian network
operator, is deploying its new optical core solution which integrates Marconi's
new family of Multihaul Dense Wavelength Division Multiplexing (DWDM) equipment,
its Optical Core Switches, including its MSH2K, and Automatic Switched Transport
Network control (ASTN). The multimillion Euro frame contract will improve
further TeliaSonera's ability to handle increasing levels of network traffic and
will reduce the cost of building and running the network.

At the heart of the Marconi solution is its SmartPhotoniX Multihaul platform,
part of Marconi's next generation network portfolio. It is a future proof
multiservice DWDM platform, designed to support new network services while
reducing operating costs.

Marconi's optical core switch platform supports an unrestricted mix of
Synchronous Digital Hierarchy (SDH) and Optical Data Units (ODU) switching, and
a distributed ASTN control-plane, reducing planning and capacity management
costs. Marconi's solution also covers system maintenance and a common network
management system.

"TeliaSonera's high capacity circuit requirements have presented a range of
challenges that we are proud to have met," said Mike Parton, Marconi chief
executive: "Carriers are increasingly turning to experts such as Marconi to find
innovative ways to cut overheads and future-proof their networks to cope with
ever-growing data loads."

ENDS/...

Notes to Editors

About Marconi's new Optical Core Switches

Marconi's new optical core switches are unique in their ability to support an
unrestricted mix of SDH and OTN switching in a single switch fabric. The optical
core switch platform scales from 80Gbit/s up to multi-terabits. The switching
capability is complemented by a distributed ASTN control-plane. This reduces
planning and capacity management costs and provides networks with self-healing
capabilities. Self-healing networks are able to reconfigure themselves in the
event of failure or damage to multiple network nodes as result of equipment
faults, natural disasters or deliberate attack. Under more routine conditions,
the control plane optimises traffic flow automatically across the network,
reducing the cost-per bit of information transferred. It does this with less
equipment than previous generation technologies and with simpler management,
installation and commissioning features such as "plug and play".

About Marconi Corporation plc
Marconi Corporation plc is a global telecommunications equipment, services and
solutions company. The company's core business is the provision of innovative
and reliable optical networks, broadband routing and switching and broadband
access technologies and services. The company's customer base includes many of
the world's largest telecommunications operators.

The company is listed on the London Stock Exchange under the symbol MONI and on
Nasdaq under the ticker MRCIY. Additional information about Marconi Corporation
can be found at www.marconi.com.

Copyright (c) 2004 Marconi Corporation plc. All rights reserved. All brands or
product names are trademarks of their respective holders.

This press release contains forward-looking statements with respect to products,
partners, customers, future growth and other matters. Please refer to the Form
20-F report, Form 10Q Reports and Form 8-K reports filed by Marconi Corporation
plc with the United States Securities and Exchange Commission for a discussion
of risks that could cause actual results to differ materially from such
statements.




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

END
AGRUUUARSKRAAAR