Holding in Company

Diploma PLC
29 March 2001


LETTER TO DIPLOMA PLC
28 MARCH 2001

Re: S.198 Companies Act 1985: as amended by The Disclosure of Interest in
    Shares (Amendment) Regulations 1993

In accordance with the Companies Act 1985, (as amended) I write to notify you
that UBS Asset Management Limited and Phillips & Drew Life Limited have an
interest in 4,002,822 ord 5p shares of the Company. This represents 15.90% of
the issued share capital of the Company.

Below is a list of the Registered holders.

UBS Asset Management Limited and Phillips & Drew Life Limited are subsidiaries
of UBS Asset Management Holding (No.2) Limited which is also treated as having
an interest in the above shares. We are authorised to make this aggregate
disclosure on behalf of UBS Asset Management Holding (No.2) Limited the
registered address of which is:

                   Triton Court
                   14 Finsbury Square
                   London EC2A 1PD

LETTER FROM PHILLIPS & DREW FUND MANAGEMENT LIMITED


                           Diploma PLC

              Total Issued Share Capital - 25,164,345

Name                                                             Quantity

CHASE NOMINEES LIMITED                          A/C GMC3          326,419
CITY OF EDINBURGH COUNCIL                       A/C LTH4           55,981
NORTHERN TRUST CO                               A/C NTH1           79,000
PHILDREW NOMINEES LIMITED                       A/C BA             37,750
PHILDREW NOMINEES LIMITED                       A/C CC             49,518
PHILDREW NOMINEES LIMITED                       A/C EO             10,300
PHILDREW NOMINEES LIMITED                       A/C FGC            36,402
PHILDREW NOMINEES LIMITED                       A/C HFM            25,500
PHILDREW NOMINEES LIMITED                       A/C LM             54,500
PHILDREW NOMINEES LIMITED                       A/C LF09           79,106
PHILDREW NOMINEES LIMITED                       A/C LF20        2,614,133
PHILDREW NOMINEES LIMITED                       A/C NEE            64,213
PHILDREW NOMINEES LIMITED                       A/C SR             18,000
PHILDREW NOMINEES LIMITED                       A/C SRB             6,000
PHILDREW NOMINEES LIMITED                       A/C TUE           407,500
PHILDREW NOMINEES LIMITED                       A/C TW            138,500
                                                                ---------
                                                                4,002,822
                                                                ---------
                                                                    15.90%