Holding(s) in Company

Spirent PLC
12 March 2004


                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of company


SPIRENT PLC



2. Name of shareholder having a major interest


BARCLAYS PLC



3. Please state whether notification indicates that it is in respect of holding
of the shareholder named in 2 above or in respect of a non-beneficial interest
or in the case of an individual holder if it is a holding of that person's
spouse or children under the age of 18


SHAREHOLDER NAMED IN 2 ABOVE



4. Name of the registered holder(s) and, if more than one holder, the number of
shares held by each of them


Registered Holder                                                            Account designation            Holding



ABBEYUTTL-6010782807-VIDACOS N                                               ABBEYUTT                       275,601

ABPEURUKQ-872482-MELLON NOMINE                                               ABPEURUK                     1,005,443

ABUEURTTL-8003168-MORGAN NOMIN                                               ABUEURTT                        64,576

ALEXITTTL-28166-CHASE NOMINEES                                               ALEXITTT                     2,971,464

ALMLUFTTL-18409-CHASE MANHATTA                                               ALMLUFTT                       487,521

ASTEXMTTL-21359-CHASE NOMINEES                                               ASTEXMTT                     1,220,660

ASUKEXTTL-20947-CHASE MANHATTA                                               ASUKEXTT                    41,814,134

AXATRKTTL-845315-MIDLAND BANK                                                AXATRKTT                        23,453

B2350FTTL-19499-CHASE MANHATTA                                               B2350FTT                       106,298

BARCLAYS CAPITAL NOMINEES LIMI                                                                              934,302

BARCLAYS TRUST CO AS EXEC/ADM                                                                                   615

BARCLAYSHARE NOMINEES LIMITED                                                                                41,330

BDFORDTTL-BCP01-NORTHERN TRUST                                               BDFORDTT                        47,353

BDUKEQTTL-N3YZ-STATE STREET                                                  BDUKEQTT                        10,446

BEUREQTTL-N3B2-STATE STREET                                                  BEUREQTT                         8,621

BLENTFUKQ-16344-CHASE MANHATTA                                               BLENTFUK                       400,264

BLENTPUKQ-16345-CHASE MANHATTA                                               BLENTPUK                       742,167

BLEQFDUKQ-16331-CHASE MANHATTA                                               BLEQFDUK                       246,435

BLEQPTUEA-16341-CHASE MANHATTA                                               BLEQPTUE                     1,964,545

BLEQPTUKQ-16341-CHASE MANHATTA                                               BLEQPTUK                       650,710

                                                                             BLFEDRTT                       122,407
BLFEDRTTL-28269-CHASE NOMINEES

BLFEPDTTL-28270-CHASE NOMINEES                                               BLFEPDTT                       716,067

BLFEPDUKQ-28270-CHASE NOMINEES                                               BLFEPDUK                       270,467

BLUKINTTL-16400-CHASE MANHATTA                                               BLUKINTT                     8,433,668

BRKSPFTTL-813168-MIDLAND BANK                                                BRKSPFTT                       926,308

BUCAPTUEA-19503-CHASE MANHATTA                                               BUCAPTUE                       258,537

BUCAPTUKQ-19503-CHASE MANHATTA                                               BUCAPTUK                       124,989

BUDISTUKA-19514-CHASE  MANHATTA                                              BUDISTUK                       128,618

BUEXINTTL-19520-CHASE MANHATTA                                               BUEXINTT                       480,956

BUFIVE350-19508-CHASE MANHATTA                                               BUFIVE35                     1,145,581

BUGENRTTL-19507-CHASE MANHATTA                                               BUGENRTT                       319,061

BUGENRUEA-19507-CHASE MANHATTA                                               BUGENRUE                       785,257

BUINCM350-19505-CHASE MANHATTA                                               BUINCM35                       209,020

BUINCMTTL-19505-CHASE MANHATTA                                               BUINCMTT                       138,568

BUINVFTTL-19518-CHASE MANHATTA                                               BUINVFTT                       662,812

BUKEQUTTL-N3B6-STATE STREET                                                  BUKEQUTT                       316,270

BUSPCSUKQ-19519-CHASE MANHATTA                                               BUSPCSUK                     2,652,018

BUTRSFTTL-19512-CHASE MANHATTA                                               BUTRSFTT                        40,008

CAAPENTTL-CVS21-NORTHERN TRUST                                               CAAPENTT                     1,692,992

CEULIPTTL-367748-BANK OF NEW Y                                               CEULIPTT                     3,599,470

CHATRKTTL-16376-CHASE MANHATTA                                               CHATRKTT                       475,611

CHRSTHUKX-16621-CHASE MANHATTA                                               CHRSTHUK                       186,353

CHUCOMTTL-31961-CHASE NOMINEES                                               CHUCOMTT                     1,347,971

CLTWORTTL-392177-BANK OF NEW Y                                               CLTWORTT                       313,638

COUEUKTTL-392067-BANK OF NEW Y                                               COUEUKTT                     4,526,598

DENTSTUKA-16644-CHASE MANHATTA                                               DENTSTUK                       420,978

DUNSWRUKA-16612-CHASE MANHATTA                                               DUNSWRUK                       154,621

DYFEDXUKA-772823-MIDLAND BANK                                                DYFEDXUK                     1,951,762

ESBSUPTTL-218311-BANK OF NEW Y                                               ESBSUPTT                        43,074

FFP350TTL-221476-BNY (OCS) NOM                                               FFP350TT                       252,149

FFPONGTTL-221428-BANK OF NEW Y                                               FFPONGTT                       524,342

FKRUSSTTL-501562755-BANKERS TR                                               FKRUSSTT                     2,023,638

FRNUKQTTL-501575013-BANKERS TR                                               FRNUKQTT                       378,406

GMITRNTTL-25772-CHASE MANHATTA                                               GMITRNTT                       595,609

INVESTORS BANK AND TRUST CO.                                                 527191                       3,056,084

INVESTORS BANK AND TRUST CO.                                                 536747                         756,438

INVESTORS BANK AND TRUST CO.                                                 552942                         355,221

INVESTORS BANK AND TRUST CO.                                                 573039                         101,088

INVESTORS BANK AND TRUST CO.                                                 585934                          10,802

INVESTORS BANK AND TRUST CO.                                                 595966                         230,692

JPMORGAN CHASE BANK                                                          540186                         181,647

JPMORGAN CHASE BANK                                                          BTGF01IE                       341,021

JPMORGAN CHASE BANK                                                          BTGF05IE                       381,288

KIOGEQUKA-387173-BNY (OCS) NOM                                               KIOGEOUK                       184,663

MARKIPTTL-814537-MIDLAND BANK                                                MARKIPTT                        80,198

MARKUKTTL-814574-MIDLAND BANK                                                MARKUKTT                        75,842

NORTHERN TRUST BANK - BGI SEPA                                               581610                         274,022

NORTHERN TRUST BANK - BGI SEPA                                               584069                         116,930

NORTHERN TRUST BANK - BGI SEPA                                               604162                          41,732

NUFFOUTTL-TNF01-NORTRUST NOMIN                                               NUFFOUTT                       329,159

NUFGENUKA-16901-CHASE MANHATTA                                               NUFGENUK                       127,521

PGUKALTTL-613363-CITIBANK NA                                                 PGUKALTT                       519,989

POWYSFTTL-16649-CHASE MANHATTA                                               POWYSFTT                        41,844

PPPMEDUKQ-8002238-DEUTSCHE BAN                                               PPPMEDUK                       127,458

PTMA11TTL-27717-CHASE NOMINEES                                               PTMA11TT                       104,456

R C GREIG NOMINEES LIMITED A/C                                               BL1                            159,633

R C GREIG NOMINEES LIMITED A/C                                               CM1                             36,608

R C GREIG NOMINEES LIMITED GP1                                               GP1                             15,218

R C GREIG NOMINEES LIMITED SA1                                               SA1                             18,461

ROYLIVTTL-LIV02-NORTRUST NOMIN                                               ROYLIVTT                       854,383

SCTPEQTLC-SCO06-NORTRUST NOMIN                                               SCTPEOTL                       308,641

STHWRKUKQ-16669-CHASE MANHATTA                                               STHWRKUK                        63,310

TORFAEUKQ-003002-MELLON NOMINE                                               TORFAEUK                        84,024

TPGEQUTTL-6948890986-CITIBANK                                                TPGEOUTT                       184,937

TRIBUNTTL-18243-CHASE MANHATTA                                               TRIBUNTT                       127,489

UNIAEQTTL-USF12-NORTHERN TRUST                                               UNIAEOTT                     2,084,752

UNLVERUKQ-USF06-NORTHERN TRUST                                               UNLVERUK                       207,560

WELLCOTTL-JD12-STATE STREET                                                  WELLCOTT                       447,165

WINUKPTTL-6010640794-VIDACOS N                                               WINUKPTT                       252,237

WOOUSFTTL-214075-BANK OF NEW Y                                               WOOUSFTT                     4,422,391

ZEBAN NOMINEES LIMITED                                                                                        1,700

ZEBAN NOMINEES LIMITED                                                                                        4,780

                                                                             TOTAL                      105,945,146

5. Number of shares / amount of stock acquired


NOT NOTIFIED



6. Percentage of issued class


NOT NOTIFIED



7. Number of shares / amount of stock disposed


-



8. Percentage of issued class


-



9. Class of security


ORDINARY SHARES OF 3.3333 PENCE EACH



10. Date of transaction


10 MARCH 2004



11. Date company informed


12 MARCH 2004



12. Total holding following this notification


105,945,146



13. Total percentage holding of issued class following this notification


11.17%



14. Any additional information


NOTIFICATION RECEIVED PURSUANT TO S198-202 COMPANIES ACT 1985 THAT THE SHAREHOLDER NAMED IN 2 ABOVE HAS INCREASED THEIR
SHAREHOLDING IN SPIRENT PLC TO 11.17%.  SHAREHOLDER PREVIOUSLY REPORTED A SHAREHOLDING OF 95,500,218 SHARES (10.07%) ON
16 FEBRUARY 2004.



15. Name of contact and telephone number for queries


LUKE THOMAS - 01293 767658



16. Name and signature of authorised company official responsible for making
this notification


LUKE THOMAS - DEPUTY COMPANY SECRETARY



Date of notification


12 MARCH 2004



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