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 March 2006

                                 SPIRENT 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 PLC

                         ANALYST / INVESTOR CONFERENCE

London, UK - 29 March 2006: Spirent plc (LSE: SPT; NYSE: SPM), a leading
communications technology company, is today holding an Analyst & Investor
Conference in the City of London.

The purpose of this event is to give attendees the opportunity to enhance their
knowledge of Spirent Communications' businesses, gain a better understanding of
the Company's products and solutions, view product demonstrations and meet key
Spirent team members. Divisional Presidents will be presenting on their
respective market segments and the product demonstrations will be run by Spirent
technicians.

A webcast of the presentations will be available on the Spirent plc website at
www.spirent.com by close of business on 30 March 2006.

No material new information will be provided and no trading update will be
given.

                                    - ends -

Enquiries

Eric Hutchinson, Finance Director    Spirent plc      +44 (0)1293 767676

Reg Hoare/Katie Hunt                 Smithfield       +44 (0) 20 7360 4900


About Spirent

Spirent 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 plc can be found at www.spirent.com

Spirent 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
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 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.

                                               ______LUKE THOMAS______

                                                     (Registrant)

Date 29 March 2006                         By   ____/s/ Luke Thomas____

                                                    (Signature)*