Trading Statement

DIPLOMA PLC

12 CHARTERHOUSE SQUARE, LONDON EC1M 6AX

TELEPHONE: +44 (0)20 7549 5700

FACSIMILE: +44 (0)20 7549 5715

FOR IMMEDIATE RELEASE

26 March 2012

DIPLOMA PLC

TRADING UPDATE

Diploma PLC, the international group of businesses supplying specialised technical products and services, is today issuing a trading update for the six months ended 31 March 2012, ahead of going into close period.

Trading Summary

Trading has continued to be strong in the second quarter and Group revenues in the first half of the financial year are expected to be ca. 12% ahead of the comparable period last year. After adjusting for currency effects and the acquisitions of CMI in December 2010 and J Royal in December 2011, underlying revenues are expected to increase by ca. 8% against a strong comparative.

The main contribution to revenue growth has been from Seals, where revenues will be substantially ahead of the comparable period last year. The North American Aftermarket business in particular has delivered an excellent performance, benefiting from continued improvement in domestic markets, but also boosted by further gains in market share. This is the most operationally leveraged part of the Group and operating margins in Seals have therefore strengthened. In Life Sciences, revenues have benefited from continued good underlying growth in the Healthcare businesses in Canada and Australia. In Controls, further steady underlying growth has been achieved with strong performances in the UK businesses more than offsetting weaker trading in Continental Europe.

With continued strong trading activity and improved operating margins in Seals, further progress in Life Sciences and Controls and contributions from businesses acquired during the year, the Board now expects the Group's adjusted profit before tax for the year ending 30 September 2012 to be ahead of the current market consensus.

Financial Position

The Group has a strong balance sheet and has a proven track record of strong cash generation. At 31 March 2012 the Group expects to be in a small net debt position, after payments of ca. £12m on acquisitions during the half year, seasonal working capital outflows and capital investment in the businesses.

The Group's results for the six months ending 31 March 2012 will be announced on Monday, 14 May 2012.

Note: A copy of this Statement, together with further information about Diploma PLC, may be viewed on its website at www.diplomaplc.com

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. 900 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. £450m.