UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                       PURSUANT TO RULE 13a-16 OR 15d-16
                     UNDER THE SECURITIES EXCHANGE ACT OF 1934




                       For the month of June , 2007

                         SPIRENT COMMUNICATIONS plc
     _____________________________________________________________________
                (Translation of registrant's name into English)

  Spirent House, Crawley Business Quarter, Fleming Way, Crawley, West Sussex
                                RH10 9QL, UK.
     _____________________________________________________________________
                    (Address of principal executive offices)


Indicate by check mark whether the registrant files or will file annual reports
under cover Form 20-F or Form 40-F.

                         Form 20-F    X         Form 40-F.....

Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

                               Yes .....        No     X

If "Yes" is marked, indicate below the file number assigned to the registrant
in connection with Rule 12g3-2(b): 82- ________





                        SPIRENT COMMUNICATIONS PLC



         TERMINATION OF REGISTRATION OF AMERICAN DEPOSITARY SHARES AND

          ORDINARY SHARES UNDER THE US SECURITIES EXCHANGE ACT OF 1934



London, UK - 6 June 2007: Spirent Communications plc ("Spirent") (LSE: SPT;
NYSE: SPM), a leading communications technology company, refers to the
announcement on 25 May 2007 of its intention to delist Spirent American
Depositary Shares ("ADS") from the New York Stock Exchange and to terminate its
registration of Spirent ADS and Ordinary shares under the US Securities Exchange
Act of 1934 ("Exchange Act"). On 5 June 2007 Spirent filed a Form 15F with the
US Securities and Exchange Commission ("SEC") thereby terminating the US
registration of its ADS and Ordinary shares. The Company's Exchange Act
reporting obligations have now ceased and termination of registration will occur
ninety days after filing, subject to the SEC having no objections.



                                    - ends -



Enquiries
Eric Hutchinson,
Chief Financial Officer     Spirent Communications plc       +44 (0)1293 767704

Paul Eardley,
Company Secretary &
General Counsel

Andrew Dowler/Harriet Keen  Financial Dynamics               +44 (0)20 7831 3113



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 that are based on
current expectations or beliefs, as well as assumptions about future events.  By
their nature, forward-looking statements are inherently predictive, 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.  These risks include the 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.


 Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

                                               ______MICHAEL ANSCOMBE______

                                                     (Registrant)

Date: 6 June, 2007                    By   ____/s/ Michael Anscombe____

                                                    (Signature)*