Holding(s) in Company

OMG PLC
06 December 2007


TR-1(i): NOTIFICATION OF MAJOR INTERESTS IN SHARES


1. Identity of the issuer or the underlying issuer of existing shares to which
voting rights are attached (ii):

OMG plc


2. Reason for the notification (please state Yes/No)

An acquisition or disposal of voting rights: (Yes)

An acquisition or disposal of financial instruments which may result in the
acquisition of shares already issued to which voting rights are attached: (No)

An event changing the breakdown of voting rights: (No)

Other (please specify): (No)


3. Full name of person(s) subject to the notification obligation (iii):

Gartmore Investment Limited

4. Full name of shareholder(s) (if different from 3.) (iv):

+-------------------------------------+----------------------------------+----------+
|Beneficial Owner                     |UK Registered Owner               |Percentage|
|                                     |                                  |of Issued |
|                                     |                                  |Capital   |
+-------------------------------------+----------------------------------+----------+
|Gartmore Fund Managers Limited       |HSBC Global Custody Nominee UK Ltd|5.569%    |
+-------------------------------------+----------------------------------+----------+
|Gartmore Investment Limited          |BNY GIL CLT A/C NOMS LTD A/C NWSC |0.467%    |
+-------------------------------------+----------------------------------+----------+
|Gartmore Investment Limited          |Nortrust Nominees Limited         |2.537%    |
+-------------------------------------+----------------------------------+----------+
|Gartmore Investment Limited          |BNY GIL CLT A/C NOMS LTD A/C LST  |1.111%    |
+-------------------------------------+----------------------------------+----------+


5. Date of the transaction (and date on which the threshold is crossed or
reached if different) (v):

30 November 2007

6. Date on which issuer notified:


3 December 2007


7. Threshold(s) that is/are crossed or reached:

Below 10 per cent.


8. Notified details:



A: Voting rights attached to shares

Class/type of shares Situation previous to the Triggering transaction
if possible using                          (vi)
the ISIN CODE
                      Number of shares  Number of voting Rights (viii)
GB0030312788                 6,721,275                       6,721,275


Resulting situation after the triggering transaction (vii)
Class/type of shares Number of shares Number of voting rights    % of voting
if possible using                              (ix)                rights
the ISIN CODE
                               Direct  Direct (x)    Indirect   Direct Indirect
                                                         (xi)
GB0030312788                6,085,857               6,085,857            9.684%


B: Financial Instruments

Resulting situation after the triggering transaction (xii)
Type of     Expiration Date  Exercise/Conversion Number of voting     % of voting
financial   (xiii)           Period/Date (xiv)   rights that may be   rights
instrument                                       acquired if the
                                                 instrument is
                                                 exercised/
                                                 converted.
N/A           N/A                 N/A                  N/A              N/A


Total (A+B)
 Number of voting rights  % of voting rights
               6,085,857              9.684%


9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable (xv):


n/a


Proxy Voting:

10. Name of the proxy holder:

n/a


11. Number of voting rights proxy holder will cease to hold:

n/a


12. Date on which proxy holder will cease to hold voting rights:

n/a


13. Additional information:


All shares are held indirectly

All figures are based on the Company's issued share capital of 62,845,162 as
provided by Exshare

E mail contact [e-mail]


14. Contact name:


RDU


15. Contact number:


0207 782 2000


Annex to Notification Of Major Interests In Shares (xvi)


A: Identity of the person or legal entity subject to the notification obligation


Full name (including legal form for legal entities):


n/a


Contact address (registered office for legal entities):


n/a


Phone number


n/a


Other useful information (at least legal representative for legal persons):

n/a


B: Identity of the notifier, if applicable (xvii)


Full name:


Gartmore Investment Limited


Contact address:


Gartmore House, 8 Fenchurch Place, London EC3M 4PB


Phone number & email:


020 7782 2324

[e-mail]


Other useful information (e.g. functional relationship with the person or legal
entity subject to the notification obligation):


Asset manager

C: Additional information

N/A



                      This information is provided by RNS
            The company news service from the London Stock Exchange