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 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(i): Notification of major interests in shares
1. Identity of the issuer or the underlying issuer of existing
shares to which voting rights are attached(ii):
Spirent Communications plc
2. Reason for the notification (please tick the appropriate box or boxes)
An acquisition or disposal of voting rights 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 notification obligation (iii):
Credit Suisse Asset Management Limited
4. Full name of shareholder(s) (if different from 3.)(iv):
HSBC Global Custody Nominees (UK) Limited
JPM Chase Nominees Limited
ROY Nominees Limited
Vidacos Nominees Limited
5. Date of the transaction (and date on which the threshold is 22/03/2007
crossed or reached if different)(v):
6. Date on which issuer notified: 26/03/2007
7. Threshold(s) that is/are crossed or reached: 6%
8. Notified details:
A: Voting rights attached to shares
Class/type of Situation previous to the Resulting situation after the triggering transaction(vii)
shares Triggering transaction (vi)
Number of Number of Number of Number of voting rights % of voting rights
if possible using Shares Voting Rights shares ix
the ISIN CODE viii Direct Direct x Indirect xi Direct Indirect
GB0004726096 52,187,604 52,187,604 55,687,604 55,687,604 0 6.28% 0
B: Financial Instruments
Resulting situation after the triggering transaction xii
Type of financial Expiration date Exercise/ Conversion Number of voting rights % of voting
instrument xiii Period/ Date xiv 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
55,687,604 6.28%
9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable xv:
Credit Suisse Asset Management Limited is a segregated business unit within
Credit Suisse Group (CSG) with an independent management structure and exercises
its voting rights independently from other parts of CSG.
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: Ross Keogh
15. Contact telephone number: 020 7888 9746
C: Additional information
Contact at Issuer: Michael Anscombe, Deputy Company Secretary, Spirent
Communications plc
Telephone: 01293 767676
--------------------------
NOTES:
(i) This form is to be sent to the issuer or underlying issuer and to
be filed with the competent authority.
(ii) Either the full name of the legal entity or another method for
identifying the issuer or underlying issuer, provided it is reliable and
accurate.
(iii) This should be the full name of (a) the shareholder; (b) the
person acquiring, disposing of or exercising voting rights in the cases provided
for in DTR5.2.1 (b) to (h); (c) all the parties to the agreement referred to in
DTR5.2.1 (a), or (d) the direct or indirect holder of financial instruments
entitled to acquire shares already issued to which voting rights are attached,
as appropriate.
In relation to the transactions referred to in points DTR5.2.1 (b) to (h), the
following list is provided as indication of the persons who should be mentioned:
- in the circumstances foreseen in DTR5.2.1 (b), the person that
acquires the voting rights and is entitled to exercise them under the agreement
and the natural person or legal entity who is transferring temporarily for
consideration the voting rights;
- in the circumstances foreseen in DTR 5.2.1 (c), the person holding
the collateral, provided the person or entity controls the voting rights and
declares its intention of exercising them, and person lodging the collateral
under these conditions;
- in the circumstances foreseen in DTR5.2.1(d), the person who has a
life interest in shares if that person is entitled to exercise the voting rights
attached to the shares and the person who is disposing of the voting rights when
the life interest is created;
- in the circumstances foreseen in DTR5.2.1 (e), the parent
undertaking and, provided it has a notification duty at an individual level
under DTR 5.1, under DTR5.2.1 (a) to (d) or under a combination of any of those
situations, the controlled undertaking;
- in the circumstances foreseen in DTR5.2.1 (f), the deposit taker of
the shares, if he can exercise the voting rights attached to the shares
deposited with him at his discretion, and the depositor of the shares allowing
the deposit taker to exercise the voting rights at his discretion;
- in the circumstances foreseen in DTR5.2.1 (g), the person that
controls the voting rights;
- in the circumstances foreseen in DTR5.2.1 (h), the proxy holder, if
he can exercise the voting rights at his discretion, and the shareholder who has
given his proxy to the proxy holder allowing the latter to exercise the voting
rights at his discretion.
(iv) Applicable in the cases provided for in DTR 5.2.1 (b) to (h). This
should be the full name of the shareholder or holder of financial instruments
who is the counterparty to the natural person or legal entity referred to in
DTR5.2.
(v) The date of the transaction should normally be, in the case of an
on exchange transaction, the date on which the matching of orders occurs; in the
case of an off exchange transaction, date of the entering into an agreement.
The date on which threshold is crossed should normally be the date on which the
acquisition, disposal or possibility to exercise voting rights takes effect (see
DTR 5.1.1R (3)). For passive crossings, the date when the corporate event took
effect.
These dates will usually be the same unless the transaction is subject to a
condition beyond the control of the parties.
(vi) Please refer to the situation disclosed in the previous
notification, In case the situation previous to the triggering transaction was
below 3%, please state 'below 3%'.
vii If the holding has fallen below the minimum threshold , the
notifying party should not be obliged to disclose the extent of the holding,
only that the new holding is less than 3%.
For the case provided for in DTR5.2.1(a), there should be no disclosure of
individual holdings per party to the agreement unless a party individually
crosses or reaches an Article 9 threshold. This applies upon entering into,
introducing changes to or terminating an agreement.
viii Direct and indirect
ix In case of combined holdings of shares with voting rights attached '
direct holding' and voting rights 'indirect holdings', please split the voting
rights number and percentage into the direct and indirect columns-if there is no
combined holdings, please leave the relevant box blank.
X Voting rights attached to shares in respect of which the notifying
party is a direct shareholder (DTR 5.1)
xi Voting rights held by the notifying party as an indirect
shareholder (DTR 5.2.1)
xii If the holding has fallen below the minimum threshold, the notifying
party should not be obliged to disclose the extent of the holding, only that the
new holding is below 3%.
xiii date of maturity / expiration of the finical instrument i.e. the
date when the right to acquire shares ends.
xiv If the financial instrument has such a period-please specify the
period- for example once every three months starting from the (date)
xv The notification should include the name(s) of the controlled
undertakings through which the voting rights are held. The notification should
also include the amount of voting rights and the percentage held by each
controlled undertaking, insofar as individually the controlled undertaking holds
3% or more, and insofar as the notification by the parent undertaking is
intended to cover the notification obligations of the controlled undertaking.
xvi This annex is only to be filed with the competent authority.
xvii Whenever another person makes the notification on behalf of the
shareholder or the natural person/legal entity referred to in DTR5.2 and
DTR5.3.
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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: 27 March 2007 By ____/s/ Michael Anscombe____
(Signature)*