Diploma Regulatory News (DPLM)

DIPLOMA PLC

12 CHARTERHOUSE SQUARE, LONDON EC1M 6AX

TELEPHONE: +44 (0)20 7549 5700

FACSIMILE: +44 (0)20 7549 5715

FOR IMMEDIATE RELEASE

24 March 2010

DIPLOMA PLC - DIRECTORS' INTERESTS IN SHARES

Diploma PLC, the international group of businesses supplying specialised technical products and services, has been notified that BM Thompson, the Chief Executive Officer of the Company, has disposed of 110,000 ordinary shares of the Company at 175.5 pence per share and has acquired, through a personal savings vehicle, 110,000 ordinary shares of the Company at 175.5 pence per share. His beneficial interest in the shares of the Company remains unchanged at 1,125,000 shares.

For further enquiries please contact:

Nigel Lingwood, Group Finance Director 020 7549 5705