Director Shareholding

Spirent PLC
10 May 2001

                               

10 May 2001

Spirent plc - NOTIFICATION OF INTERESTS OF DIRECTOR

Spirent plc announced on 9 May 2001 that Mr My Chung had been appointed
to the Board as an Executive Director with immediate effect. The
following notification relates to the interests held by Mr Chung, for
which-nil consideration has been paid in all cases.

INTEREST IN THE US ALL EMPLOYEE STOCK PURCHASE PLAN 
At the date of his appointment,Mr Chung was interested provisionally in 1,518
options granted at a provisional exercise price of 544.0 pence per Ordinary
share under the terms of the Company's US All Employee Stock Purchase Plan (the
'US Plan'). The exercise price and number of options exercisable under
the US Plan cannot be ultimately determined until the maturity of the
offering period (which in this case is expected to be the exercise date
of 1 November 2001). The number of options and exercise price as stated
are based on the market price of a Spirent Ordinary share as at the date
of grant less an applicable 15% discount, pursuant to the rules of the US
Plan.

INTEREST IN DISCRETIONARY SHARE OPTION SCHEMES 

At the date of his appointment, Mr Chung held the following interests in respect
of share options granted under the Company's Executive Share Option Scheme and
the Spirent Stock Option Plan:

* Total number of options held: 1,138,956

* Period during which options exerciseable: 11 May 2001 - 8 April 2011

* Consideration paid for grant of options: Nil

* Range of option exercise prices per Ordinary share: 133.05 pence -
612.5 pence

INTEREST IN RIGHTS UNDER THE DISCRETIONARY NETCOM STOCK APPRECIATION
RIGHTS PLAN 

At the date of his appointment, Mr Chung held an interest in
42,740 rights under the Company's Netcom Stock Appreciation Rights Plan
(the 'NSARP) at an award price of 335 pence per Ordinary share. The NSARP
will deliver the appreciation value (i.e. the aggregated increase in the
market value of a Spirent Ordinary share over the rights price) in the
form of existing Spirent Ordinary shares. The rights are exerciseable
between 12 May 2001 and 11 May 2010.

INTEREST IN THE DISCRETIONARY LONG TERM SHARE PURCHASE PLAN

At the date of his appointment, Mr Chung held a total of 88,893
Performance Units at award prices of between 305 pence and 334.11 pence
per Unit under the terms of the Company's long Term Share Purchase Plan
('LTSPP')(the 'Grant'). A Performance Unit is equivalent to one Ordinary
share of the Company.

Subject to and in accordance with the rules and the operation of the
LTSPP, the range of dates for the first performance period in respect of
the Grant are the three years starting from 1 January 2000 and 1 January
2001. The range of dates for the second performance period in respect of the
Grant will be the three years starting from 1 January 2003 and 1 January 2004.

In respect of the first performance period, the value of the reward will
be based on the increase in value of the Performance Units between the
date of each respective Grant and the third anniversary of the Grant. In
respect of the second performance period, the value of the Grant cannot
be determined since Mr Chung has an entitlement to make an election to
take any-reward value in-the form of either Company shares and/or cash.

NON BENEFICIAL INTEREST IN SHARES

On appointment, Mr Chung received a deferred share bonus award of 39,620
Ordinary shares in the Company, pursuant to the terms of an Annual
Incentive Bonus Plan. The award consists of market purchased shares
granted to Mr Chung at an award price of 310 pence per share (being the
mid market closing price of a Spirent Ordinary share on 9 May 2001). The
shares are registered under Orbis Pension Trustees Limited T1019 (the
'Trustee'), the Trustee of Spirent's employee benefit trust established
to deliver Spirent Ordinary shares under various discretionary employee
share schemes and under the Annual Bonus Incentive Plan. The Trustee will
hold the shares for a period of three years. Entitlement to the 39,620
shares is therefore deferred for three years and whilst Mr Chung does not
currently have a beneficial interest in these shares he does now have a
notifiable interest in the same.

OTHER STATUTORY DEEMED INTERESTS IN SHARES

Mr Chung is a potential beneficiary of shares held by the above mentioned
Trustee (together with his fellow executive directors and all other
participating employees) and is therefore treated under the Companies Act
1985 as having a technical interest in the total number of shares held by
the Trustee. As a result, Mr Chung has a deemed interest in 9,064,985
Ordinary shares (representing 0.98% of the issued share capital), being
the total number of Ordinary shares held by the Trustee.

If you have any queries, please do not hesitate to contact the writer on Tel:
01293 767 676.



Michael Arnaouti
Company Secretary