Regulatory News Announcement

RNS Number:3856X
O2 PLC
24 January 2006


NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Name of company

O2 plc

2. Name of shareholder having a major interest

Telefonica S.A.

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

In respect of 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                             Number of Shares

Vidacos No 65 A/C                             652,356,107 *

Goldman Sachs Securities (Nominees) Limited 95,250,000

Telefonica became interested in 5,964,008,947 shares by virtue of its offer for
the entire issued and to be issued share capital of O2 not already owned by
Telefonica at the date of the offer (the 'Offer') being declared unconditional
in all respects as announced on 23 January 2006. It is intended that these
shares will be registered in the name of Telefonica once settlement and
registration has taken place.

The registered holder of the remaining 14,422 Ordinary shares of O2 plc in which
Telefonica is interested is not know at the date of this notification.

* 340,356,107 shares are currently registered in the name of Vidacos No 65 A/C
and it is intended that the remaining 312,000,000 shares referred to above will
be registered in the name of Vidacos No 65 A/C once settlement and registration
has taken place.

5. Number of shares / amount of stock acquired

Not stated

6. Percentage of issued class

N/A

7. Number of shares / amount of stock disposed

Not stated

8. Percentage of issued class

N/A

9. Class of security

Ordinary shares of 0.1p each

10. Date of transaction

Statement of holdings as at 6am on 23 January 2006

11. Date company informed

23 January 2006

12. Total holding following this notification

6,711,629,476

13. Total percentage holding of issued class following this notification

76.51%

14. Any additional information

Notification in respect of section 198 Companies Act 1985

15. Name of contact and telephone number for queries

Timothy Maw - 01753 628 293

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

Timothy Maw

Date of notification

24 January 2006

The FSA does not give any express or implied warranty as to the accuracy of this
document or material and does not accept any liability for error or omission.
The FSA is not liable for any damages (including, without limitation, damages
for loss of business or loss of profits) arising in contract, tort or otherwise
from the use of or inability to use this document, or any material contained in
it, or from any action or decision taken as a result of using this document or
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                      This information is provided by RNS
            The company news service from the London Stock Exchange

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