Exhibit (a)(11) - Press Release issued by Thomson on July 12, 2000.


The Thomson Corporation                                     [LOGO]
Toronto Dominion Bank Tower, Suite 2706
PO Box 24, Toronto-Dominion Centre
Toronto, Ontario M5K 1A1
Tel (416) 360-8700   Fax (416) 360-8812
www.thomson.com


News Release


Investor Contact:                       Media Contact:
- ----------------                        -------------
John Kechejian                          Janey Loyd
Vice President, Investor Relations      Vice President, Corporate Communications
(203) 969-8700                          (203) 969-8700
john.kechejian@thomson.com              janey.loyd@thomson.com



For Immediate Release
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                         THE THOMSON CORPORATION EXTENDS
                  ITS EQUITY AND DEBT TENDER OFFERS FOR PRIMARK

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         TORONTO, ONTARIO, July 12, 2000 - The Thomson Corporation (TSE: TOC)
announced today that Marquee Acquisition Corporation ("Marquee"), a wholly owned
subsidiary of Thomson, is extending its offer to acquire all outstanding shares
of common stock of Primark Corporation until Friday, August 4, 2000 at 12:00
midnight Eastern Daylight Time (EDT). The offer to acquire the common stock of
Primark was previously scheduled to expire at 12:00 midnight EDT on Wednesday,
July 12, 2000.

         In addition, Thomson announced that Marquee is extending its offer to
acquire all of the outstanding Primark 9 1/4% Senior Subordinated Notes due 2008
(the "Notes") until Monday, August 7, 2000 at 12:00 midnight EDT. The offer to
acquire the Notes was previously scheduled to expire at 5:00 p.m. EDT on
Thursday, July 20, 2000.

         Thomson and Primark previously announced that they had each received
requests for additional information and documentary material from the Antitrust
Division of the Department of Justice (DOJ) following the DOJ's routine review
of the proposed acquisition of Primark by Thomson. The waiting period under the
Hart-Scott-Rodino Act will expire ten days after Thomson substantially complies
with the DOJ's request.

         Based on the latest count of tendered shares and Notes, as of 5:00 p.m.
EDT on July 11, 2000, 8,445,103 shares of Primark common stock (constituting
41.6% of the outstanding common stock) had been tendered and not withdrawn, and
US$149.9 million in the aggregate principal amount of the Notes (constituting
99.9% of the outstanding Notes) had been tendered and not withdrawn.

         After the receipt by Marquee of the requisite consents pursuant to its
Offer to Purchase the Notes and related Consent Solicitation, Primark and State
Street Bank and Trust Company, as trustee, have executed a supplemental
indenture today amending the indenture dated December 21, 1998 governing the
Notes. The provisions of the supplemental indenture will not become operative
unless and until Marquee accepts for payment the Notes that have been validly
tendered and not withdrawn prior to August 7, 2000.



         The tender offer for the Primark common stock is being made through,
and the foregoing announcement is qualified in its entirety by reference to,
Marquee's Offer to Purchase dated June 14, 2000, and the related letter of
transmittal. The tender offer for the Notes is being made through, and the
foregoing announcement is qualified in its entirety by reference to, Marquee's
Offer to Purchase and Consent Solicitation Statement dated June 22, 2000, and
the related letter of transmittal. Primark stockholders and noteholders should
read the applicable Offer to Purchase and related letter of transmittal in their
entirety prior to making any decision as to the respective tender offers.

         The Thomson Corporation (www.thomson.com), with 1999 revenues of US$5.8
billion, is a leading, global e-information and solutions company in the
business and professional marketplace. Thomson's common shares are listed on the
Toronto and London Stock Exchanges.

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