SOURCE: Spirent Communications PLC

May 25, 2007 10:22 ET

Spirent Communications PLC announces Holding(s) in Company - 1

Crawley, UK -- (MARKET WIRE) -- May 25, 2007 --

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              Aviva plc and 
notification obligation (iii):                        its subsidiaries 

4. Full name of shareholder(s) (if different from 3.)(iv):

    Registered Holder:

    BNY Norwich Union Nominees Limited                        10,789,155*
    Chase GA Group Nominees Limited                           17,599,819*
    Chase Nominees Limited                                     1,818,129*
    CUIM Nominee Limited                                       7,614,113*
    Vidacos Nominees Limited                                     227,769*

    * denotes direct interest


5. Date of the transaction (and date on which the threshold is   
crossed or reached if different)(v):

22 May 2007

6. Date on which issuer notified:                                

24 May 2007


7. Threshold(s) that is/are crossed or reached:                  

3% to 4% Change at Direct Interest level

8. Notified details:

A: Voting rights attached to shares

Class/type    Situation previous to    Resulting situation after the triggering transaction(vii)
of shares     the Triggering
              transaction (vi)
if possible   Number of    Number of   Number of    Number of voting rights  % of voting rights
using the     Shares       Voting      shares       ix
ISIN CODE                  Rights viii Direct       Direct  x   Indirect xi  Direct    Indirect

Ordinary 
Shares
GB0004726096  27,209,781   27,209,781  38,048,985   38,048,985  Not          4.32%     Not
                                                                disclosable            disclosable






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


Total (A+B)
Number of voting rights                            % of voting rights

38,048,985                                         4.32%



9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable xv:
                                                     
See Section 4


Proxy Voting:

10. Name of the proxy holder:                                     

See Section 4

11. Number of voting rights proxy holder will cease to hold:

12. Date on which proxy holder will cease to hold voting rights:


13. Additional information:                 

Figures are based on a total number of voting rights of 880,671,085.

14. Contact name:                           Neil Whittaker

15. Contact telephone number:               01603 684420


C:        Additional information


Contact at Issuer: Michael Anscombe, Deputy Company Secretary, 
Spirent Communications plc

Telephone:            01293 767672


--------------------------


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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