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 May, 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- ________
TR-1: NOTIFICATION OF MAJOR INTERESTS IN SHARES
1. Identity of the issuer or the underlying issuer of existing
shares to which voting rights are attached:
Spirent Communications plc
2. Reason for the notification (please tick the appropriate box or boxes)
An acquisition or disposal of voting rights - DISPOSAL X
An acquisition or disposal of financial instruments which may result
in the acquisition of shares already issued to which voting rights are
attached
An event changing the breakdown of voting rights
Other (please specify)
3. Full name of person(s) subject to the (i) Lexa BV
notification obligation:
(ii) Goran Ennerfelt (a non-executive director of
Spirent Communications plc) has a connected interest
in the shareholding of Lexa BV. This is due to the
fact that he is President and Chief Executive Officer
of Axel Johnson AB, a member of the Axel Johnson Group
which owns Lexa BV.
4. Full name of shareholder(s) (if different -
from 3.):
5. Date of the transaction (and date on which the 22 May 2007
threshold is crossed or reached if different):
6. Date on which issuer notified: 22 May 2007
7. Threshold(s) that is/are crossed or reached: Below 10 %
8. Notified details: Sold 40,400,000
Ordinary shares
A: Voting rights attached to shares
Class/type of Situation previous to Resulting situation after the triggering transaction
shares the Triggering
transaction
if possible Number of Number of Number of Number of voting rights ix % of voting rights
using the ISIN Shares Voting shares
CODE Rights viii Direct Direct x Indirect xi Direct Indirect
Ordinary shares 90,400,000 90,400,000 50,000,000 50,000,000 N/A 5.67 N/A
ISIN:
GB0004726096
B: Financial Instruments
Resulting situation after the triggering transaction
Type of financial Expiration date Exercise/ Conversion Number of voting rights % of voting
instrument Period/ Date that may be acquired if rights
the instrument is
exercised/ converted.
N/A N/A N/A N/A N/A
Total (A+B)
Number of voting rights % of voting rights
50,000,000 5.67%
9. Chain of controlled undertakings through which the voting rights and/or
the financial instruments are effectively held, if applicable :
(i) Lexa BV
(ii) Goran Ennerfelt (a non-executive director of Spirent Communications plc)
has a connected interest in the shareholding of Lexa BV. This is due to the
fact that he is President and Chief Executive Officer of Axel Johnson AB, a
member of the Axel Johnson Group which owns Lexa BV.
Proxy Voting:
10. Name of the proxy holder: N/A
11. Number of voting rights proxy holder will cease to hold: N/A
12. Date on which proxy holder will cease to hold voting N/A
rights:
13. Additional information: N/A
14. Contact name: Arie Bouman - Managing Director, LEXA BV
15. Contact telephone number: +31 (0)20 471 3438
C: Additional information
Contact at Issuer: Michael Anscombe, Deputy Company Secretary,
Spirent Communications plc
Telephone: 01293 767676
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: 22 May, 2007 By ____/s/ Michael Anscombe____
(Signature)*