Charles River Laboratories Acquires Northwest Kinetics, Inc.

Establishes Phase I Clinical Capacity in North America 

WILMINGTON, Mass. -- Charles River Laboratories International, Inc. (NYSE: CRL) announced today that it has acquired privately held Tacoma, Washington-based Northwest Kinetics, Inc. for $29.5 million dollars. The acquisition establishes a Phase I clinical services capacity in North America, which in conjunction with Charles River's Phase I facility in Edinburgh, Scotland, positions the Company exceptionally well to support its clients' high-end clinical pharmacology studies and further expands Charles River's leadership role in preclinical and early clinical development.

Northwest Kinetics is a 150-bed facility with expertise in branded-drug studies. It is currently in the process of expanding to 250 beds, which provides a platform for continued growth. When the expansion is completed in the fourth quarter of 2006, in combination with the Phase I facility in Scotland, the Company will have a total capacity of more than 300 beds.

Charles River expects the transaction will be neutral to earnings on a GAAP basis, and slightly accretive on a non-GAAP basis, in 2007.

James C. Foster, Chairman, President and Chief Executive Officer said, "Our mission is to support our clients' drug development needs from discovery to preclinical development to Phase I clinical trials, and the acquisition of Northwest Kinetics meets a key objective in strengthening our Phase I service offerings. With this acquisition, we can now offer high-end clinical pharmacology services in North America, complementing our presence in Scotland. Through its management's deep scientific and medical backgrounds, Northwest Kinetics has established itself as a premier provider of branded drug studies, and we expect to leverage that expertise on a global basis as we expand our Phase I service offerings. Northwest Kinetics' scientific excellence and outstanding customer service make it a superb fit for us, as these are the hallmarks of Charles River. We are very pleased to welcome Northwest Kinetics to the Charles River family."

Caution Concerning Forward-Looking Statements. This news release 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," "will," "may," "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 include the statements in this press release regarding Charles River's expectations with respect to its ability to expand the capacity of the Tacoma facility and the expected impact of the acquisition on the Company's earnings. Forward-looking statements are based on Charles River's current expectations and beliefs, and involve a number of risks and uncertainties that are difficult to predict and that could cause actual results to differ materially from those stated or implied by the forward-looking statements. A further description of these risks, uncertainties, and other matters can be found in the Risk Factors detailed in Charles River's Annual Report on Form 10-K as filed on March 14, 2006, as well as other filings we make with the Securities and Exchange Commission. Charles River assumes no obligation and expressly disclaims any duty to update information contained in this release except as required by law.

About Charles River Laboratories

Charles River Laboratories based in Wilmington, Massachusetts, partners with global pharmaceutical and biotechnology companies, government agencies and leading academic institutions to advance the drug discovery and development process, bringing drugs to market faster and more efficiently. Charles River's 7,500 employees serve clients worldwide. For more information on Charles River, visit our website at www.criver.com.