Holding(s) in Company

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 notification (yes/no)

An acquisition or disposal of voting rights

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): Decrease in the number of total voting rights in Spirent Communications plc resulting from a Tender Offer

Yes

3. Full name of person(s) subject to notification obligation:

(i) Hayden Investors Partners II, LLC;

(ii) Sherborne Investors LP;

(iii) Sherborne Investors GP, LLC;

(iv) Craig L. McKibben;

(v) Gerard L. Eastman, Jr.; and

(vi) Edward Bramson

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

Noted below:

Person named in 3. above

Shareholder

No. of shares

(i)

Hanover Nominees Limited

40,844,268 Ordinary Shares

(ii) - (v)

Hanover Nominees Limited

130,250,000 Ordinary Shares (aggregate)

(vi)

(a) Hanover Nominees Limited

130,250,000 Ordinary Shares (aggregate)

(b) Merrill Lynch, Pierce, Fenner & Smith, Inc.

20,000 Ordinary Shares

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

November 27, 2008 (being the date of the Result of Tender Offer announcement)

6. Date on which issuer notified:

November 27, 2008

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

(i) Hayden Investors Partners II, LLC - 6%;

(ii) Sherborne Investors LP - 19% (aggregate);

(iii) Sherborne Investors GP, LLC - 19% (aggregate);

(iv) Craig L. McKibben - 19% (aggregate);

(v) Gerard L. Eastman, Jr. - 19% (aggregate); and

(vi) Edward Bramson - 19% (aggregate).

Please note, for the purposes of this TR-1 notification, the only entities which have triggered a new notification obligation under the Disclosure and Transparency Rules are those entities noted in 3. above.

None of Hayden Investors Partners, LLC, Sherborne Strategic Fund A, LLC or Sherborne Strategic Fund B, LLC has reached, exceeded or fallen below a relevant threshold as a result of Spirent Communications plc's recent tender offer completion.

8. Notified Details

A: Voting rights attached to shares

Class/type of shares

If possible use 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

Percentage of voting rights

Direct

Direct

Indirect

Direct

Indirect

ISIN:

GB0004726096

130,250,000

130,250,000

130,250,000

N/A

130,250,000

N/A

19.27%

ISIN:

GB0004726096

20,000

20,000

20,000

20,000

N/A

0.003%

N/A

B: Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date

Exercise/ conversion period/date 

No. of voting rights that may be acquired (if the instrument is exercised/converted)

Percentage of voting rights

N/A

N/A

N/A

N/A

N/A

Total (A+B)

Number of voting rights

Percentage of voting rights

130,270,000

19.27%

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

Edward Bramson is the managing member and Craig L. McKibben and Gerard L. Eastman Jr. are members of Sherborne Investors GP, LLC. Sherborne Investors GP, LLC is the general partner of Sherborne Investors LP, which is the managing member of each of the following funds (all of which hold Ordinary Shares in the issuer through Hanover Nominees Limited):

Hayden Investors Partners, LLC (45,685,845 Ordinary Shares - approximately 6.76% - no new individual notification required, see response to 7. above);

Hayden Investors Partners II, LLC (40,844,268 Ordinary Shares - approximately 6.04% - such figure being a subject of this notification of major interest in shares);

Sherborne Strategic Fund A, LLC (29,644,000 Ordinary Shares - approximately 4.39% - no new individual notification required, see response to 7. above);

Sherborne Strategic Fund B, LLC (14,075,887 Ordinary Shares - approximately 2.08% - no new individual notification required, see response to 7. above);

Edward Bramson holds 20,000 further Ordinary Shares through Merrill Lynch, Pierce, Fenner & Smith, Inc.

Proxy Voting:

10. Name of 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 rights:

N/A

13. Additional information:

N/a

14 Contact name:

Craig L. McKibben

15. Contact telephone name:

+1 (212) 735 1000

Additional information

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

Telephone: 01293 767672