UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 6-K
REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934
For the month of March 2006
SPIRENT plc
_____________________________________________________________________
(Translation of registrant's name into English)
Spirent House, Crawley Business Quarter, Fleming Way, Crawley, West Sussex
RH10 9QL, UK.
_____________________________________________________________________
(Address of principal executive offices)
Indicate by check mark whether the registrant files or will file annual reports
under cover Form 20-F or Form 40-F.
Form 20-F X Form 40-F.....
Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.
Yes ..... No X
If "Yes" is marked, indicate below the file number assigned to the registrant
in connection with Rule 12g3-2(b): 82- ________
NOTIFICATION OF MAJOR INTERESTS IN SHARES
1. Name of listed company
SPIRENT PLC
2. Name of shareholder with a major interest
BARCLAYS PLC
3. Please state whether notification indicates that regarding the holding of the
shareholder named in 2 above; 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 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
BARCLAYS CAPITAL NOMINEES LIMITED -126,801
BARCLAYS CAPITAL NOMINEES LIMITED -76,469
BARCLAYS CAPITAL NOMINEES LIMITED 554,239
BARCLAYS CAPITAL NOMINEES LIMITED 2,003,740
Barclays Trust Co & Others 8,077
BNP PARIBAS 51,000
BOISS NOMINEES LTD 4224361 594,977
CHASE NOMINEES LTD 16376 527,631
CHASE NOMINEES LTD 20947 29,775,272
CHASE NOMINEES LTD 21359 1,483,196
CHASE NOMINEES LTD 28270 307,679
CHASE NOMINEES LTD 28270 908,176
CIBC MELLON GLOBAL SECURITIES 42,140
Gerrard Nominees Limited 642367 13,000
Gerrard Nominees Limited 650668 13,000
Gerrard Nominees Limited 653035 13,000
Gerrard Nominees Limited 660632 6,000
Gerrard Nominees Limited 660758 35,000
Gerrard Nominees Limited 660851 30,000
Greig Middleton Nominees Limited (GM1) 200,787
INVESTORS BANK AND TRUST CO. 221,432
INVESTORS BANK AND TRUST CO. 22,464
INVESTORS BANK AND TRUST CO. 56,359
INVESTORS BANK AND TRUST CO. 1,770,097
INVESTORS BANK AND TRUST CO. 699,748
INVESTORS BANK AND TRUST CO. 54,686
JP MORGAN (BGI CUSTODY) 16331 268,775
JP MORGAN (BGI CUSTODY) 16341 2,160,554
JP MORGAN (BGI CUSTODY) 16341 560,581
JP MORGAN (BGI CUSTODY) 16344 687,727
JP MORGAN (BGI CUSTODY) 16345 1,158,601
JP MORGAN (BGI CUSTODY) 16400 9,479,907
JP MORGAN (BGI CUSTODY) 18409 791,821
JPMorgan Chase Bank 555,319
JPMorgan Chase Bank 399,337
Mellon Trust - US CUSTODIAN / 81,846
MELLON TRUST OF NEW ENGLAND 81,368
NORTHERN TRUST BANK - BGI SEPA 136,835
NORTHERN TRUST BANK - BGI SEPA 120,848
NORTHERN TRUST BANK - BGI SEPA 35,400
R C Greig Nominees Limited 921,916
R C Greig Nominees Limited a/c AK1 705,551
R C Greig Nominees Limited a/c BL1 97,464
R C Greig Nominees Limited a/c CM1 24,646
R C Greig Nominees Limited GP1 50,096
R C Greig Nominees Limited SA1 31,232
STATE STREET TRUST OF CANADA - 77,145
The Northern Trust Company - U 54,943
Total 57,670,342
5. Number of shares / amount of stock acquired
-
6. Percentage of issued class (any treasury shares held by the listed company
should not be taken into account when calculating percentage)
-
7. Number of shares / amount of stock disposed
NOT KNOWN
8. Percentage of issued class (any treasury shares held by the listed company
should not be taken into account when calculating percentage)
NOT KNOWN
9. Class of security
ORDINARY SHARES OF 3.3333 PENCE EACH
10. Date of transaction
HOLDING AS AT 23 MARCH 2006
11. Date company informed
28 MARCH 2006
12. Total holding following this notification
57,670,342
13. Total percentage holding of issued class following this notification (any
treasury shares held by the listed company should not be taken into account when
calculating percentage)
5.95%
14. Any additional information
SHAREHOLDER PREVIOUSLY REPORTED A SHAREHOLDING OF 105,727,030 (10.91%) ON 14
MARCH 2006.
15. Name of contact and telephone number for queries
MICHAEL ANSCOMBE - 01293 767672
16. Name and signature of duly authorised company official of the listed company
responsible for making this notification
MICHAEL ANSCOMBE - DEPUTY COMPANY SECRETARY
Date of notification
28 MARCH 2006
Signatures
Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.
______LUKE THOMAS______
(Registrant)
Date 28 March, 2006 By ____/s/ Luke Thomas____
(Signature)*