Holding(s) in Company

RNS Number : 4252Q

Spirent Communications PLC

03 August 2010

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESⁱ

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 qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached
An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments			X
An event changing the breakdown of voting rights
Other (please specify):
3. Full name of person(s) subject to the notification obligation: ⁱⁱⁱ	BlackRock, Inc.
4. Full name of shareholder(s) (if different from 3.):^iv
5. Date of the transaction and date on which the threshold is crossed or reached: ^v	29^th July 2010
6. Date on which issuer notified:	2^nd August 2010
7. Threshold(s) that is/are crossed or reached: ^{vi, vii}	Holding has gone above 17%

8. Notified details:

A: Voting rights attached to shares ^{viii, ix}

Class/type of
shares

if possible using
the ISIN CODE

Situation previous
to the triggering
transaction

Resulting situation after the triggering transaction

Number
of
Shares

Number
of
Voting
Rights

Number
of shares

Number of voting
rights

% of voting rights ^x

Direct

Direct ^xi

Indirect ^xii

Direct

Indirect

GB0004726096

79,161,757

N/A

83,096,790

N/A

12.31%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial
instrument

Expiration
date ^xiii

Exercise/
Conversion Period ^xiv

Number of voting
rights that may be
acquired if the
instrument is
exercised/ converted.

% of voting
rights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments ^{xv, xvi}

Resulting situation after the triggering transaction

Type of financial
instrument

Exercise price

Expiration date ^xvii

Exercise/
Conversion period ^xviii

Number of voting rights instrument refers to

% of voting rights ^{xix, xx}

CFD

N/A

35,705,552

Nominal

Delta

5.29%

Total (A+B+C)

Number of voting rights

Percentage of voting rights

118,802,342

17.59%

9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable: ^xxi
BlackRock Investment Management (UK) Limited - 118,802,342 (17.59%)

Proxy Voting:
10. Name of the proxy holder:
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:	BlackRock Threshold Reporting Team
14. Contact name:	Stuart Watchorn
15. Contact telephone number:	020 7743 5741; stuart.watchorn@blackrock.com