Diploma Regulatory News (DPLM)

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

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

Diploma Plc

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

An acquisition or disposal of voting rights

ü

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 notification obligation:

FMR LLC

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

See attached schedule

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

06 December 2010

6. Date on which issuer notified:

08 December 2010

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

5%

8. Notified details:

A: Voting rights attached to shares

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights

Direct

Direct

Indirect

Direct

Indirect

GB0001826634

5,707,367

5,707,367

5,657,367

5,657,367

4.99

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/ConversionPeriod

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

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

Resulting situation after the triggering transaction

Type of financialinstrument

Exerciseprice

Expirationdate

Exercise/Conversionperiod

Number of votingrights instrumentrefers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

5,657,367

4.99

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

See attached schedule

Proxy Voting:

10. Name of the proxy holder:

FMR LLC

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

50,000

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

06 December 2010

13. Additional information:

None

14. Contact name:

Robert Crayston

15. Contact telephone number:

fil-regreportinq@fil.com

FMR

Issuer name:

 DIPLOMA PLC

Current ownership percentage:

4.99%

Total shares held:

 5,657,367

Issued share capital:

 113,239,555

SHARES HELD

NOMINEE

MANAGEMENT COMPANY

FMR LLC is the parent holding company of Fidelity Management & Research Company (FMRCO) Investment Manager for US mutal Funds and FIL Management Trust

Company (FMTC) and Pyramid Global Advisors Trust Company (PGATC), a US Chartered Bank which acts as a trustee or Investment Manager of various pension and trust accounts

and Pyramid Global Advisors LLC (PGALLC)

2,050,000

STATE STREET BANK AND TR CO

FMR

3,607,367

STATE STREET BANK AND TR CO

FMRCO