Holding(s) in Company

PRESS ANNOUNCEMENT

FOR IMMEDIATE RELEASE

17 MAY 2010

HAMWORTHY PLC

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

1.

Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached:

Hamworthy plc

2.

Reason for notification (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

An event changing the breakdown of voting rights

Other (please specify):

3.

Full name of person(s) subject to notification obligation:

Schroders plc

4.

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

n/a

5.

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

14 May 2010

6.

Date on which issuer notified:

17 May 2010

7.

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

12% - 13%

8.

Notified Details

A:

Voting rights attached to shares

Class/type of shares

Situation previous to the triggering transaction

Resulting situation after the triggering transaction

If possible use ISIN code

Number of shares

Number of voting rights

Number of shares

Number of voting rights

Percentage of voting rights

Direct

Direct

Indirect

Direct

Indirect

Ordinary

GB00B01VFV79

6,080,652

5,867,627

6,116,311

N/A

5,903,286

N/A

13.05%

B:

Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date

Exercise/ conversion period/date

No. of voting rights that may be acquired (if the instrument exercised/converted)

Percentage of voting rights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Exercise price

Expiration date

Exercise/ Conversion period

Number of voting rights instrument refers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

5,903,286

13.05%

9.

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

Schroder Investment Management Limited 5,046,922 (11.15%)

Schroder Investment Management North America Limited 856,364 (1.89%)

Proxy Voting:

10.

Name of 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:

The shares referred to in section 9 are held in portfolios managed by those firms on a discretionary basis for clients under investment management agreements.

14.

Contact name:

Taryn O'Donoghue

15.

Contact telephone name:

020 7658 6000