Holding(s) in Company

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:

 Rotork Plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

YES

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

NO

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

NO

An event changing the breakdown of voting rights

 NO

Other (please specify):

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

 William Blair & Company, LLC

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

5. Date of the transaction and date on which the threshold is crossed or reached:

 16.06.2010

6. Date on which issuer notified:

 18.06.2010

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

 Fell below 5% threshold

8. Notified details:

A: Voting rights attached to shares

Class/type of shares

if possible using the ISIN CODE

Situation previous to the triggering transaction

Resulting situation after the triggering transaction

Number of Shares

Number of Voting Rights

Number of shares

Number of voting rights

% of voting rights

Direct

Direct

Indirect

Direct

Indirect

GB0007506958

4,423,559

4,423,559

3,803,107

 3,803,107

 4.4%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date

Exercise/ Conversion Period

Number of voting rights that may be acquired if the instrument is exercised/ converted.

% of voting rights

 N/A

N/A

N/A

N/A

N/A

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

 3,803,107

 4.4%

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

William Blair & Company, L.L.C. (William Blair) is an investment adviser registered under the U.S. Investment Advisers Act of 1940. As such, pursuant to advisory contracts, William Blair has the power to purchase and sell securities on behalf of its clients and the power to vote for most clients. Persons other than William Blair are entitled to receive all dividends from, and

proceeds from the sale of all securities reported hereunder.

Proxy Voting:

10. Name of the proxy holder:

 William Blair & Company, LLC

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:

14. Contact name:

 Stephen Rhys Jones

15. Contact telephone number:

01225 733331