Thomson Completes Acquisition of TradeWeb

STAMFORD, Conn., May 24, 2004 -- The Thomson Corporation (NYSE: TOC; TSX:TOC) announced today that it has completed the acquisition of privately held TradeWeb Group LLC. Thomson purchased TradeWeb for $385 million in cash plus contingent payments of up to approximately $150 million over the next three years based on the achievement of growth targets.

Thomson Financial's content and analytic tools together with TradeWeb's fixed income expertise will provide the opportunity to extend and accelerate Thomson Financial's penetration and reach in the growing institutional fixed-income market.

Upon close of the transaction, Jim Toffey will report directly to Sharon Rowlands, president and COO, Thomson Financial. Mr. Toffey will continue run TradeWeb and will assume responsibility for all of Thomson Financial's fixed-income assets. In addition, current President of TradeWeb Lee Olesky will continue in his current role and report to Mr. Toffey.

The Thomson Corporation

The Thomson Corporation (www.thomson.com), with 2003 revenues from continuing operations of $7.6 billion, is a global leader in providing integrated information solutions to business and professional customers. Thomson provides value-added information, software tools and applications to more than 20 million users in the fields of law, tax, accounting, financial services, higher education, reference information, corporate training and assessment, scientific research and healthcare. With operational headquarters in Stamford, Conn., Thomson has approximately 39,000 employees and provides services in approximately 130 countries. The Corporation's common shares are listed on the New York and Toronto stock exchanges (NYSE: TOC; TSX: TOC).