Holding(s) in Company

+------------------------------------------------------------------------------+
|TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi                               |
+------------------------------------------------------------------------------+

+----------------------------------------------+-------------------------------+
|1. Identity of the issuer or the underlying   |                               |
|issuer                                        |        Weir Group Plc         |
|of existing shares to which voting rights are |                               |
|attached: ii                                  |                               |
+----------------------------------------------+-------------------------------+
|2 Reason for the notification (please tick the appropriate box or boxes):     |
+---------------------------------------------------------------------+--------+
|An acquisition or disposal of voting rights                          |   X    |
+---------------------------------------------------------------------+--------+
|An acquisition or disposal of qualifying financial instruments which |        |
|may result in the acquisition of shares already issued to which      |        |
|voting rights are attached                                           |        |
+---------------------------------------------------------------------+--------+
|An acquisition or disposal of instruments with similar economic      |        |
|effect to qualifying financial instruments                           |        |
+---------------------------------------------------------------------+--------+
|An event changing the breakdown of voting rights                     |        |
+---------------------------------------------------------------------+--------+
|Other (please specify):                                              |        |
+--------------------------------------+------------------------------+--------+
|3. Full name of person(s) subject to  |                                       |
|the                                   |   Prudential plc group of companies   |
|notification obligation: iii          |                                       |
+--------------------------------------+---------------------------------------+
|4. Full name of shareholder(s)        |         See attached schedule         |
|(if different from 3.):iv             |                                       |
+--------------------------------------+---------------------------------------+
|5. Date of the transaction and date on|                                       |
|which the threshold is crossed or     |             22 June 2011              |
|reached: v                            |                                       |
+--------------------------------------+---------------------------------------+
|6. Date on which issuer notified:     |             23 June 2011              |
+--------------------------------------+---------------------------------------+
|7. Threshold(s) that is/are crossed or|              See item 13              |
|reached: vi, vii                      |                                       |
+--------------------------------------+---------------------------------------+

+----------------------------------------------------------------------------------+
|8. Notified details:                                                              |
+----------------------------------------------------------------------------------+
|A: Voting rights attached to shares viii, ix                                      |
+------------+----------------------+----------------------------------------------+
|Class/type  |Situation previous    |Resulting situation after the triggering      |
|of          |to the triggering     |transaction                                   |
|shares      |transaction           |                                              |
|            +----------+-----------+----------+-------------------+---------------+
|if possible |Number    |Number     |Number    |Number of voting   |% of  voting   |
|using       |of        |of         |of shares |rights             |rights x       |
|the ISIN    |  ares    |V ting     +----------+----------+--------+------+--------+
|CODE        |          |Rights     |Direct    |Direct xi |Indirect|Direct|Indirect|
|            |          |           |          |          |xii     |      |        |
+------------+----------+-----------+----------+----------+--------+------+--------+
|GB0009465807|11,572,094|11,572,094 |11,110,617|11,110,617|        |5.25% |        |
+------------+----------+-----------+----------+----------+--------+------+--------+
|            |          |           |          |          |        |      |        |
+------------+----------+-----------+----------+----------+--------+------+--------+

+----------------------------------------------------------------------------------+
|B: Qualifying Financial Instruments                                               |
+----------------------------------------------------------------------------------+
|Resulting situation after the triggering transaction                              |
+--------------+----------+---------------------+--------------------+-------------+
|Type of       |Expiration|Exercise/            |Number of voting    |% of voting  |
|financial     |date xiii |Conversion Period xiv|rights that may be  |rights       |
|instrument    |          |                     |acquired if the     |             |
|              |          |                     |instrument is       |             |
|              |          |                     |exercised/          |             |
|              |          |                     |converted.          |             |
+--------------+----------+---------------------+--------------------+-------------+
|              |          |                     |                    |             |
+--------------+----------+---------------------+--------------------+-------------+

+----------------------------------------------------------------------------------+
|C: Financial Instruments with similar economic effect to Qualifying Financial     |
|Instruments xv, xvi                                                               |
+----------------------------------------------------------------------------------+
|Resulting situation after the triggering transaction                              |
+-------------+---------+----------+-----------+--------------------+--------------+
|Type of      |Exercise |Expiration|Exercise/  |Number of voting    |% of voting   |
|financial    |price    |date xvii |Conversion |rights instrument   |rights xix, xx|
|instrument   |         |          |period     |refers to           |              |
|             |         |          |xviii      |                    |              |
+-------------+---------+----------+-----------+--------------------+-------+------+
|             |         |          |           |                    |Nominal|Delta |
|             |         |          |           |                    +-------+------+
|             |         |          |           |                    |       |      |
+-------------+---------+----------+-----------+--------------------+-------+------+

+----------------------------------------------------------------------------------+
|Total (A+B+C)                                                                     |
+------------------------------------+---------------------------------------------+
|Number of voting rights             |Percentage of voting rights                  |
+------------------------------------+---------------------------------------------+
|11,110,617                          |5.25%                                        |
+------------------------------------+---------------------------------------------+

+------------------------------------------------------------------------------+
|9. Chain of controlled undertakings through which the voting rights and/or the|
|financial instruments are effectively held, if applicable: xxi                |
+------------------------------------------------------------------------------+
|Prudential plc (parent Company)                                               |
|M&G Group Limited (wholly owned subsidiary of Prudential plc)                 |
|M&G Limited (wholly owned subsidiary of M&G Group Limited)                    |
|M&G Investment Management Limited (wholly owned subsidiary of M&G Limited)    |
|The Prudential Assurance Company Limited (wholly owned subsidiary of          |
|Prudential plc)                                                               |
|                                                                              |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Proxy Voting:                                                                 |
+-----------------------------------------------+------------------------------+
|10. Name of the proxy holder:                  |             N/A              |
+-----------------------------------------------+------------------------------+
|11. Number of voting rights proxy holder will  |                              |
|cease                                          |             N/A              |
|to hold:                                       |                              |
+-----------------------------------------------+------------------------------+
|12. Date on which proxy holder will cease to   |                              |
|hold                                           |             N/A              |
|voting rights:                                 |                              |
+-----------------------------------------------+------------------------------+

+-----------------------------+------------------------------------------------+
|                             |                                                |
|13. Additional information:  |The Prudential Assurance Company Limited (wholly|
|                             |owned subsidiary of Prudential plc) has gone    |
|                             |below a 5% notifiable interest, triggering this |
|                             |notification.                                   |
+-----------------------------+------------------------------------------------+
|14. Contact name:            |Ajay Patel / Mark Thomas                        |
|                             |M&G Investment Management Limited               |
+-----------------------------+------------------------------------------------+
|15. Contact telephone number:|020 7548 3261 / 020 7548 3266                   |
+-----------------------------+------------------------------------------------+







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Source: The Weir Group PLC via Thomson Reuters ONE

[HUG#1526224]