OTTAWA, Canada - September 12, 2005 - Galazar Networks® Inc. is supplying key semiconductor solutions for multiservice provisioning platforms (MSPP) to Marconi Corporation plc (London: MONI and NASDAQ: MRCIY). Recent network wins for Marconi with a number of major operators have included products supporting next generation SONET/SDH features enabled by Galazar’s MSF250™ and DSF250™ products.

The ability to efficiently carry Ethernet services on existing SDH network infrastructure using Generic Framing Procedure (GFP), high order and low order Virtual Concatenation (VCAT) and Link Capacity Adjustment Scheme (LCAS) is a key decision criterion for many network operators. Galazar offers a product line that supports the features required for the evolving network as well as the software and support to assure successful system implementation.

Rod Smith, Managing Director of Marconi's Northern Europe business, said: "Marconi has been winning new network deployments worldwide based on our ability to enhance existing SDH networks at lower cost and with technology that will support a reliable migration to NGN (next generation network)."

"Many network equipment vendors and carriers have been successfully deploying next generation networking platforms by leveraging Galazar’s capabilities," said Richard Deboer, CEO, Galazar Networks. "We believe that Marconi’s growing success with their MSPP products validates their commitment to supporting carriers with robust products with the right features. Galazar is proud to be a part of that."

About Galazar Networks Inc.
Galazar Networks Inc. is a leading semiconductor vendor focused on framers for carrier grade Ethernet over SONET/SDH (EoS) and Multi-Service line cards. Our products support SONET/SDH, PDH (DS3/E3, DS1/E1), data (Ethernet, packet, private line) and SAN services (Fibre Channel, FICON, ESCON, Gigabit Ethernet). Galazar is a technology leader in Generic Framing Protocol (GFP), Virtual Concatenation (VCAT) of both High and Low Order paths, and Link Capacity Adjustment Scheme (LCAS). Galazar’s products are ideal for Ethernet, SAN and Multi-Service CPE/CLE platforms as well as EoS, PoS and SAN line cards for ADMs, routers, MSTPs and Metro Core switches. For more information, visit www.galazar.com.

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, broadband access technologies and services. The company's customer base includes many of the world's largest telecommunications operators. For more information, visit www.marconi.com.

The company is listed on the London Stock Exchange under the symbol MONI and on NASDAQ under the ticker MRCIY.

This press release contains forward-looking statements with respect to products, partners, customers, future growth and other matters. Please refer to the Form 10-K report 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.

For more information or to arrange for interviews, please contact: