US Delisting & Deregistration

Spirent Communications PLC
25 May 2007


                           SPIRENT COMMUNICATIONS PLC

              VOLUNTARY DELISTING FROM THE NEW YORK STOCK EXCHANGE

                 AND DEREGISTRATION FROM THE US SECURITIES AND

                              EXCHANGE COMMISSION



London, UK - 25 May 2007: Spirent Communications plc ("Spirent" or "the 
Company")(LSE: SPT; NYSE: SPM), a leading communications technology company,
announces its intention to delist its American Depositary Shares ("ADS") from
the New York Stock Exchange ("NYSE") and to deregister from the US Securities
and Exchange Commission ("SEC").

The average daily trading volume of shares represented by Spirent's ADS is very
small, accounting for 0.5% of the total number of Spirent Ordinary shares traded
in the most recent 12 month period.  In light of this level of trading activity
and the recent adoption of new rules by the SEC regarding the termination of
reporting obligations under US securities laws, Spirent believes that the
administrative burden and increasing costs associated with maintaining its
listing on the NYSE and the reporting requirements necessary for its
registration with the SEC under the US Securities Exchange Act of 1934 ("the
Exchange Act") outweigh the benefits to Spirent and its shareholders.

Spirent intends to maintain its American Depositary Receipt facility with The
Bank of New York as a Level 1 Programme.  This means that the Company's ADS will
be traded in the US over-the-counter ("OTC") market with effect from 15 June
2007.  The Company's Ordinary shares will continue to trade on the London Stock
Exchange.

Although Spirent wishes to reduce the costs and complexity of complying with the
US securities regulations, it remains fully committed to its business operations
in the United States and also to maintaining high standards of corporate
governance and transparency toward its shareholders.  Through its listing on the
London Stock Exchange, Spirent will remain subject to the listing rules, the
prospectus rules and the disclosure and transparency rules made by the UKLA and
to the Combined Code on Corporate Governance.

Spirent expects that its application for delisting from the NYSE will be
submitted so as to become effective on 14 June 2007 and that it will submit its
application to the SEC to terminate its Exchange Act reporting obligations with
effect from 4 June 2007.



                                    - ends -



Enquiries
Edward Bramson, Executive Chairman         Spirent Communications plc   [phone]
Eric Hutchinson, Chief Financial Officer

Andrew Dowler/Harriet Keen                 Financial Dynamics           [phone]



About Spirent Communications plc

Spirent Communications plc is a leading communications technology company
focused on delivering innovative systems and services to meet the needs of
customers worldwide.  We are a global provider of performance analysis and
service assurance solutions that enable the development and deployment of
next-generation networking technologies such as broadband services, Internet
telephony, 3G wireless and web applications and security testing.  The Systems
group develops power control systems for specialist electrical vehicles in the
mobility and industrial markets.  Further information about Spirent
Communications plc can be found at www.spirent.com.

Spirent Communications plc Ordinary shares are traded on the London Stock
Exchange (ticker: SPT) and on the New York Stock Exchange (ticker: SPM; CUSIP
number: 84856M209) in the form of American Depositary Shares ("ADS"),
represented by American Depositary Receipts, with one ADS representing four
Ordinary shares.

Spirent and the Spirent logo are trademarks or registered trademarks of Spirent
Communications plc.  All other trademarks or registered trademarks mentioned
herein are held by their respective companies.  All rights reserved.



This press release may contain forward-looking statements (as that term is
defined in the United States Private Securities Litigation Reform Act of 1995)
based on current expectations or beliefs, as well as assumptions about future
events.  You can sometimes, but not always, identify these statements by the use
of a date in the future or such words as "will", "anticipate", "estimate",
"expect", "project", "intend", "plan", "should", "may", "assume" and other
similar words.  By their nature, forward-looking statements are inherently
predictive and speculative and involve risk and uncertainty because they relate
to events and depend on circumstances that will occur in the future.  You should
not place undue reliance on these forward-looking statements, which are not a
guarantee of future performance and are subject to factors that could cause our
actual results to differ materially from those expressed or implied by these
statements.  Such factors include, but are not limited to: the extent to which
customers continue to invest in next-generation technology and deploy advanced
IP-based services; our ability to manage a significant transition in product
revenues to new product solutions incorporating latest technology; the
implementation of the operating review; the outcome of the business review; our
ability to successfully expand our customer base; continuing variable market
conditions; pace of economic recovery; our ability to improve efficiency,
achieve the benefits of our cost reduction goals and adapt to economic changes
and other changes in demand or market conditions; our ability to develop and
commercialise new products and services, extend our existing capabilities in IP
services and expand our product offering internationally; our ability to attract
and retain qualified personnel; the effects of competition on our business;
fluctuations in exchange rates and heavy exposure to the US dollar; changes in
the business, financial condition or prospects of one or more of our major
customers; risks of doing business internationally; risks relating to the
acquisition or sale of businesses and our subsequent ability to integrate
businesses; our reliance on proprietary technology; our exposure to liabilities
for product defects; our reliance on third party manufacturers and suppliers;
and other risks described from time to time in Spirent Communications plc's
Securities and Exchange Commission periodic reports and filings.  The Company
undertakes no obligation to update any forward-looking statements contained in
this press release, whether as a result of new information, future events or
otherwise.




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            The company news service from the London Stock Exchange