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Exhibit 99.1 Charles River Laboratories Announces Third - Quarter 2021 Results - Third - Quarter Revenue of $ 895.9 Million - - Third - Quarter GAAP Earnings per Share of $ 2.01 and Non - GAAP Earnings per Share of $ 2.70 - - Updates 2021 Guidance - WILMINGTON , Mass .-- ( BUSINESS WIRE ) -- November 3 , 2021 -- Charles River Laboratories International , Inc. ( NYSE : CRL ) today reported its results for the third quarter of 2021. For the quarter , revenue was $ 895.9 million , an increase of 20.5 % from $ 743.3 million in the third quarter of 2020 . Acquisitions contributed 5.9 % to consolidated third - quarter revenue growth . The impact of foreign currency translation benefited reported revenue growth by 1.0 % . Excluding the effect of these items , organic revenue growth was 13.6 % , driven by contributions from all three business segments . The comparison to last year's COVID - 19 - related impact increased the reported and organic revenue growth rates in the third quarter of 2021 by 1.8 % and 1.7 % , respectively . On a GAAP basis , third - quarter net income attributable to common shareholders was $ 103.4 million , an increase of 0.5 % from net income of $ 102.9 million for the same period in 2020. Third - quarter diluted earnings per share on a GAAP basis were $ 2.01 , a decrease of 1.0 % from $ 2.03 for the third quarter of 2020. GAAP net income and earnings per share reflect higher revenue and a lower tax rate , which were offset by venture capital investment losses . GAAP net income and earnings per share included a loss from the Company's venture capital and other strategic investments of $ 0.15 per share in the third quarter of 2021 , compared to a gain of $ 0.29 per share for the same period in 2020. The Company's venture capital and other strategic investment performance has been excluded from non - GAAP results . On a non - GAAP basis , net income was $ 139.1 million for the third quarter of 2021 , an increase of 17.9 % from $ 118.0 million for the same period in 2020. Third - quarter diluted earnings per share on a non - GAAP basis were $ 2.70 , an increase of 15.9 % from $ 2.33 per share for the third quarter of 2020. The non - GAAP net income and earnings per share increases were primarily driven by higher revenue and a lower tax rate . James C. Foster , Chairman , President and Chief Executive Officer , said , “ Our strong third - quarter results demonstrate the effectiveness of our strategy , the sustained strength of industry fundamentals , and the success we have had in becoming our clients ' partner of choice from concept , to nonclinical development , to the safe manufacture of their life - saving therapeutics . "