Spirent Regulatory News (SPT)

FORM 8.3

PUBLIC OPENING POSITION DISCLOSURE/DEALING DISCLOSURE BY

A PERSON WITH INTERESTS IN RELEVANT SECURITIES REPRESENTING 1% OR

MORE

Rule 8.3 of the Takeover Code (the "Code")

1.

KEY INFORMATION

(a)

Full name of discloser:

Barclays PLC.

(b)

Owner or controller of interest and short

positions disclosed, if different from 1(a):

(c)

Name of offeror/offeree in relation to whose

SPIRENT COMMUNICATIONS PLC

relevant securities this form relates:

(d)

If an exempt fund manager connected with an

offeror/offeree, state this and specify identity of

offeror/offeree:

(e)

Date position held/dealing undertaken:

26 Sep 2025

(f)

In addition to the company in 1(c) above, is the discloser making

NO

disclosures in respect of any other party to the offer?

2.

POSITIONS OF THE PERSON MAKING THE DISCLOSURE

(a)

Interests and short positions in the relevant securities of the offeror or offeree

to which the disclosure relates following the dealing(if any)

Class of relevant security:

3 1/3p ordinary

Interests

Short Positions

Number

(%)

Number

(%)

(1)

Relevant securities owned

and/or controlled:

24,122,816

4.09%

9,893,363

1.68%

(2)

Cash-settled derivatives:

9,735,417

1.65%

24,160,890

4.10%

(3)

Stock-settled derivatives (including options)

and agreements to purchase/sell:

0

0.00%

0

0.00%

TOTAL:

33,858,233

5.74%

34,054,253

5.77%

(b)

Rights to subscribe for new securities (including directors and other executive

options)

Class of relevant security in relation to

which subscription right exists

Details, including nature of the rights

concerned and relevant percentages:

3.

DEALINGS (IF ANY) BY THE PERSON MAKING THE DISCLOSURE

(a)

Purchases and sales

Class of relevant

Purchase/sale

Number of

Price per unit

security

securities

3 1/3p ordinary

Purchase

438,053

1.9590 GBP

3 1/3p ordinary

Purchase

106,773

1.9521 GBP

3 1/3p ordinary

Purchase

57,346

1.9587 GBP

3 1/3p ordinary

Purchase

40,591

1.9531 GBP

3 1/3p ordinary

Purchase

25,758

1.9520 GBP

3 1/3p ordinary

Purchase

21,128

1.9533 GBP

3 1/3p ordinary

Purchase

7,699

1.9560 GBP

3 1/3p ordinary

Purchase

4,892

1.9540 GBP

3 1/3p ordinary

Purchase

4,827

1.9600 GBP

3 1/3p ordinary

Purchase

3,549

1.9580 GBP

3 1/3p ordinary

Purchase

888

1.9596 GBP

3 1/3p ordinary

Purchase

125

1.9550 GBP

3 1/3p ordinary

Sale

500,000

1.9592 GBP

3 1/3p ordinary

Sale

182,977

1.9590 GBP

3 1/3p ordinary

Sale

145,047

1.9520 GBP

3 1/3p ordinary

Sale

31,543

1.9518 GBP

3 1/3p ordinary

Sale

31,247

1.9540 GBP

3 1/3p ordinary

Sale

24,384

1.9538 GBP

3 1/3p ordinary

Sale

19,459

1.9545 GBP

3 1/3p ordinary

Sale

8,676

1.9535 GBP

3 1/3p ordinary

Sale

3,660

1.9600 GBP

3 1/3p ordinary

Sale

3,549

1.9580 GBP

3 1/3p ordinary

Sale

3,072

1.9549 GBP

3 1/3p ordinary

Sale

2,623

1.9560 GBP

3 1/3p ordinary

Sale

734

1.9524 GBP

3 1/3p ordinary

Sale

654

1.9550 GBP

(b)

Cash-settled derivative transactions

Class of

Product

Nature of dealing

Number of

Price per

relevant

description

reference

unit

security

securities

3 1/3p ordinary

SWAP

Increasing Short

10,593

1.9558 GBP

3 1/3p ordinary

SWAP

Decreasing Short

31,543

1.9518 GBP

3 1/3p ordinary

SWAP

Decreasing Short

4,461

1.9520 GBP

3 1/3p ordinary

SWAP

Decreasing Short

734

1.9524 GBP

3 1/3p ordinary

SWAP

Decreasing Short

6,380

1.9526 GBP

3 1/3p ordinary

SWAP

Decreasing Short

9,333

1.9538 GBP

3 1/3p ordinary

SWAP

Decreasing Short

4,724

1.9539 GBP

3 1/3p ordinary

SWAP

Decreasing Short

24,701

1.9540 GBP

3 1/3p ordinary

SWAP

Decreasing Short

4,877

1.9569 GBP

3 1/3p ordinary

SWAP

Decreasing Short

2,240

1.9580 GBP

3 1/3p ordinary

SWAP

Decreasing Short

182,977

1.9590 GBP

3 1/3p ordinary

SWAP

Increasing Short

7,380

1.9520 GBP

3 1/3p ordinary

SWAP

Increasing Short

1,410

1.9539 GBP

3 1/3p ordinary

SWAP

Increasing Short

10,774

1.9548 GBP

3 1/3p ordinary

SWAP

Increasing Short

3,853

1.9560 GBP

3 1/3p ordinary

SWAP

Increasing Short

2,661

1.9600 GBP

3 1/3p ordinary

CFD

Decreasing Short

7,925

1.9544 GBP

(c)

Stock-settled derivative transactions (including options)

(i)

Writing, selling, purchasing or varying

Class

Product

Writing,

Number

Exercise

Type

Expiry

Option

of

description

purchasing,

of

price

date

money

relevant

selling,

securities

per unit

paid/

security

varying etc

to which

received

option

per unit

relates

(ii)

Exercise

Class of relevant

Product description

Exercising/ exercised against

Number of

Exercise price per

security

securities

unit

(d)

Other dealings (including subscribing for new securities)

Class of relevant

Nature of Dealings

Details

Price per unit (if

security

applicable)

4.

OTHER INFORMATION

(a)

Indemnity and other dealings arrangements

Details of any indemnity or option arrangement, or any agreement or understanding,

formal or informal, relating to relevant securities which may be an inducement to deal

or refrain from dealing entered into by the exempt principal trader making the disclosure and any party

to the offer or any person acting in concert with a party to the offer:

NONE

(b)

Agreements, arrangements or understandings relating to options or derivatives

Details of any agreement, arrangement or understanding, formal or informal, between

the person making the disclosure and any other person relating to:

(i) the voting rights of any relevant securities under any option; or

(ii) the voting rights of future acquisition or disposal of any relevant securities to which

any derivative is referenced:

NONE

(c)

Attachments

Is a Supplemental Form 8 (Open Positions) attached?

NO

Date of disclosure:

29 Sep 2025

Contact name:

Large Holdings Regulatory Operations

Telephone number:

020 3134 7213