Charles River Laboratories Names Dr. Nancy Gillett President of Global Pre-Clinical Services.

WILMINGTON, Mass. -- - Integration Related Organizational Changes Align Management and Strategy -

- Proteomics Joint Venture To Close -

Charles River Laboratories International, Inc. (NYSE:CRL) announced today that in connection with the integration of Charles River and Inveresk Research Group, Dr. Nancy Gillett has been named Senior Vice President and President, Global Pre-Clinical Services, succeeding Mr. Michael Ankcorn, who is retiring from the Company on December 31, 2004. Mr. Glenn Kerkhof has been named Interim President, Global Clinical Services, succeeding Mr. Alastair McEwan, who is leaving the Company on December 10, 2004.

Commenting on the changes, Mr. James C. Foster, Chairman, President and Chief Executive Officer, said, "Through the merger with Inveresk, we had a unique opportunity to strengthen our management team, and to draw on the best talent available across the organization. Dr. Gillett is an excellent choice to assume these new responsibilities. She has deep expertise and extensive experience in her field, and will play a critical role in Charles River's goal to be the premier global company advancing the search for drugs, devices and therapies from discovery through market approval."

Mr. Foster continued, "Mr. Kerkhof has done an excellent job in his role as Vice President Operations, Clinical Europe and Asia-Pacific, and we believe he will do equally well as overseer of the global clinical business until a successor is announced."

Mr. Foster said, "We are very appreciative of the contributions that Michael Ankcorn and Alastair McEwan have made to building Inveresk's well-respected and highly successful pre-clinical and clinical operations, and for their efforts on the merger and integration processes. We wish them both continuing success in their future endeavors."

Dr. Gillett, formerly Corporate Vice President and President, U.S. Pre-Clinical Services, was the chief architect of the integration of the Company's Discovery & Development Services (DDS) business. Over the past two years, Dr. Gillett has restructured and streamlined that business, positioning it as one of the three major players in the market for outsourced pre-clinical services. Dr. Gillett, who holds D.V.M. and Ph.D. degrees, is an ACVP board-certified pathologist with twenty years of experience in scientific research and management.

Mr. Kerkhof, who is Vice President Operations, Clinical Europe and Asia-Pacific, has been with Inveresk for eleven years, during which time he was instrumental in establishing Inveresk as a significant European presence in the clinical services business. When Inveresk acquired ClinTrials (2001) and PharmaResearch (2003), Mr. Kerkhof was responsible for the integrations of the European clinical operations. With each acquisition, Mr. Kerkhof restructured the operations, improving profitability and implementing sales strategies to enhance sales growth.

Assuming the role of General Manager and President, U.S. Pre-Clinical Services, is Paul A. Oskar III. Mr. Oskar has been with Charles River for twenty-two years, and has extensive knowledge and experience in managing and providing strategic direction to a wide range of high-growth service businesses. He had been Executive Director of Laboratory Services until December 2003, when he was promoted to General Manager, DDS Worcester Division. In that role, Mr. Oskar has been responsible for managing the largest of Charles River's U.S. pre-clinical facilities, where he reorganized the operation and developed strategic sales initiatives that improved sales and profitability. Mr. Oskar has played a key role in the integration of Charles River and Inveresk to date, and will continue to do so in his new role.

Mr. Christopher Perkin, currently Chief Operating Officer of CTBR, has been named General Manager and President, Canadian Pre-Clinical Services. With thirty-five years of industry experience, Mr. Perkin has extensive knowledge and expertise in operations and strategic management of pre-clinical services. Through his sixteen years with Inveresk, Mr. Perkin played an instrumental role in developing Inveresk's Canadian pre-clinical business and building it into one of the pre-eminent facilities in the world. Mr. Perkin is a Diplomate of the American Board of Toxicology.

Dr. Brian Bathgate, currently Corporate Vice President and President, European Pre-Clinical Services, will continue in that role. Mr. Oskar, Mr. Perkin and Dr. Bathgate will report to Dr. Gillett.

As part of the reorganization of DDS Worcester Division and the integration of the worldwide pre-clinical services organization, the Company has decided to close Charles River Proteomic Services (CRPS), a joint venture established with Proteome Systems Ltd. in the fourth quarter of 2002. CRPS, which was established to provide proteomic research services on a fee-for-service basis, has not achieved its strategic goals. The closure is expected to result in a one-time write-off of approximately $0.02 to $0.03 per diluted share in the fourth quarter. The charge will be recorded in the fourth quarter of 2004. Closure of CRPS is expected to improve Charles River's profitability in 2005.

Upcoming 2005 Guidance Meeting

Charles River Laboratories will discuss the management changes and provide guidance for 2005 at its meeting for investors on Wednesday, December 15, 2004, in New York. The meeting will be webcast on the Company's website at ir.criver.com. Please contact Charles River's Investor Relations Department for further information.

About Charles River Laboratories

Charles River Laboratories (CRL), based in Wilmington, Massachusetts, is a global provider of solutions that advance the drug discovery and development process. Our leading-edge products and services are designed to enable our clients to bring drugs to market faster and more efficiently. Backed by our rigorous, best-in-class procedures and our proven data collection, analysis and reporting capabilities, our products and services are organized into three categories spanning every step of the drug development pipeline: Research Models and Services, Pre-Clinical Services, and Clinical Services. CRL's customer base includes all of the major pharmaceutical companies, biotechnology companies, government agencies and many leading hospitals and academic institutions. Charles River's 8,000 employees serve clients in more than 50 countries. For more information on CRL, visit our website at www.criver.com.

Caution Concerning Forward-Looking Statements. This document includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as "anticipate," "believe," "expect," "estimate," "plan," "outlook," and "project" and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. Forward-looking statements are based on Charles River's current expectations and beliefs, and involve a number of risks and uncertainties that could cause actual results to differ materially from those stated or implied by the forward-looking statements. Those risks and uncertainties include, but are not limited to: challenges arising from the merger with Inveresk Research Group; a decrease in research and development spending or a decrease in the level of outsourced services; acquisition integration risks; special interest groups; contaminations; industry trends; new displacement technologies; USDA and FDA regulations; changes in law; continued availability of products and supplies; loss of key personnel; interest rate and foreign currency exchange rate fluctuations; changes in tax regulation and laws; changes in generally accepted accounting principles; and any changes in business, political, or economic conditions due to the threat of future terrorist activity in the U.S. and other parts of the world, and related U.S. military action overseas. A further description of these risks, uncertainties, and other matters can be found in the Risk Factors detailed in Charles River's Registration Statement on Form S-4 as filed on September 16, 2004, with the Securities and Exchange Commission. Because forward-looking statements involve risks and uncertainties, actual results and events may differ materially from results and events currently expected by Charles River, and Charles River assumes no obligation and expressly disclaims any duty to update information contained in this news release except as required by law.