Pre-Close Update

DIPLOMA PLC

12 CHARTERHOUSE SQUARE, LONDON EC1M 6AX

TELEPHONE: +44 (0)20 7549 5700

FACSIMILE: +44 (0)20 7549 5715

FOR IMMEDIATE RELEASE

24 September 2012

DIPLOMA PLC

PRE-CLOSE STATEMENT

YEAR ENDING 30 SEPTEMBER 2012

Diploma PLC, the international group of specialised businesses supplying technical products and services, is today providing the following update on trading for the year ending 30 September 2012.

The Company anticipates reporting a strong set of results for the year ending 30 September 2012 in line with market consensus. Revenues for the year are expected to be ca. 13% ahead of those reported last year. After adjusting for currency effects and acquisitions, underlying revenues for the year are expected to have increased by ca. 6%. The underlying increase in fourth quarter revenues is likely to be 5% which is unchanged from the third quarter increase. Strong cash flows in the final quarter of the year will result in year end net cash being strongly positive.

Operating margins remain ahead of the prior year, but below the record level of 20.8% reported in the first half of this financial year, as the Group makes good progress with its planned investments in new facilities, IT and senior management to support the future growth of the business.

The Preliminary Results for the year ending 30 September 2012 will be announced on Monday, 19 November 2012. There will be a presentation to analysts of the results at 9.00am, at Butchers' Hall, 87 Bartholomew Close, City of London, EC1A 7EB.

For further information, please contact:

NOTE TO EDITORS:

Diploma PLC is an international group of businesses supplying specialised technical products and services to the Life Sciences, Seals and Controls industries.

Diploma's businesses are focussed on supplying essential products and services which are funded by the customers' operating rather than their capital budgets, providing recurring income and stable revenue growth.

Our businesses then design their individual business models to closely meet the requirements of their customers, offering a blend of high quality customer service, deep technical support and value adding activities. By supplying essential solutions, not just products, we build strong long term relationships with our customers and suppliers, which support attractive and sustainable margins.

Finally we encourage an entrepreneurial culture in our businesses through our decentralised management structure. We want our managers to feel that they have the freedom to run their own businesses, while being able to draw on the support and resources of a larger group. These essential values ensure that decisions are made close to the customer and that the businesses are agile and responsive to changes in the market and the competitive environment.

The Group employs ca. 1,000 employees and its principal operating businesses are located in the UK, Germany, US and Canada.

Over the last five years, the Group has grown adjusted earnings per share at an average of ca. 19% p.a. through a combination of organic growth and acquisitions. Diploma is a member of the FTSE 250 with a market capitalisation of ca. £500m.

Further information on Diploma PLC can be found at www.diplomaplc.com