Sigma-Aldrich Acquires Ultrafine to Enhance Fine Chemicals Capabilities

ST. LOUIS – April 14, 2004 – Sigma-Aldrich Corporation (Nasdaq: SIAL) announced today that it has enhanced its Fine Chemicals capabilities to serve pharmaceutical and biotech manufacturers through its acquisition of Ultrafine. Founded in 1984 and institutionally backed, Ultrafine is located in Manchester, U.K. and is a leading supplier of contract chemistry services for all phases of drug development to customers world-wide, with capabilities ranging from fundamental research to GMP manufacturing, including the ability to supply active ingredients for clinical trials. Ultrafine’s life science catalogue also currently offers more than 130 products which enable its customers to expedite drug discovery and development.

The acquisition is expected to add approximately one percent to Sigma-Aldrich’s otherwise reportable growth in the remaining quarters of 2004. Acquired operations are expected to meet or exceed the Company’s targets of 10% annualized, local currency growth over the next several years and to be accretive to earnings in and after 2004, with no initial charges. Terms of the purchase, which were not disclosed, were paid in cash.

Commenting on the acquisition, Frank Wicks, President, Sigma-Aldrich Fine Chemicals said, “Ultrafine reinforces and enhances our Fine Chemicals capabilities and is an ideal complement to our existing cGMP process development and manufacturing facilities in the UK, USA and Switzerland. Combining Ultrafine’s medicinal chemistry skills and ability to rapidly provide preclinical and early clinical phase GMP material with Sigma-Aldrich Fine Chemicals’ capabilities in process development and scale up, we are now better positioned to meet the demands of the pharmaceutical industry for high quality products and services through all stages of development, enabling customers to get their new products to market more quickly.”

John Fromson, Ultrafine’s departing Chairman added, “As we have worked through this transaction, I have found the two companies have the same values and cultures. Joining our businesses makes the most sense for our staff, providing them with enhanced opportunities for career progression, and for our customers as it offers them a broader spectrum of development support, particularly in manufacturing, where Sigma-Aldrich has state-of-the-art facilities. I expect to see Ultrafine grow and prosper under its new ownership.”

Mike Harris, Ultrafine’s Business Development head, added, “This will be extremely beneficial to our customers, allowing us to provide continuous support all the way from early drug discovery chemistry through process development to full-scale API manufacture in world class facilities.”

Fairmount Partners, a boutique life sciences investment banking firm out of Philadelphia, PA, represented the Ultrafine investors in the transaction, including 3I Group PLC and Renaissance Ventures LP.

ABOUT SIGMA-ALDRICH

Sigma-Aldrich is a leading Life Science and High Technology company. Its biochemical and organic chemical products and kits are used in scientific and genomic research, biotechnology, pharmaceutical development, the diagnosis of disease and chemical manufacturing. Sigma-Aldrich has customers in life science companies, university and government institutions, hospitals and in industry. Over one million scientists and technologists use its products. Sigma-Aldrich operates in 34 countries and has 5,900 employees providing excellent service worldwide. The company is committed to the success of its Customers, Employees and Shareholders through leadership in Life Science, High Technology and Service. For more information about Sigma-Aldrich, please visit its award-winning web site sigma-aldrich.com .

Principals of Fairmount Partners are acting as advisors to Ultrafine in connection with the acquisition.

Contact:
Cornelius “Neal” P. McCarthy