Rule 8.3 - THOMSON CORP

FORM 8.3

    DEALINGS BY PERSONS WITH INTERESTS IN SECURITIES REPRESENTING 1% OR MORE
              (Rule 8.3 of the City Code on Takeovers and Mergers)


1.   KEY INFORMATION

Name of person dealing        BARCLAYS PLC
(Note 1)
Company dealt in              THOMSON CORP
Class of relevant security    COM NPV
to which the dealings being
disclosed relate (Note 2)
Date of dealing               05 March 2008

2.   INTERESTS, SHORT POSITIONS AND RIGHTS TO SUBSCRIBE

(a)  Interests and short positions (following dealing) in the class of relevant
security dealt in (Note 3)

                            Long                     Short

                      Number       (%)         Number       (%)

(1) Relevant       7,391,300      1.16%      804,352       0.13%
securities
(2) Derivatives      658,796      0.10%
(other than
options)
(3) Options and            0      0.00%            0       0.00%
agreements to
purchase/sell
Total              8,050,096      1.26%      804,352       0.13%


(b)  Interests and short positions in relevant securities of the company, other
     than the class dealt in (Note 3)

Class of                    Long                     Short
relevant
security:

                  Number              (%)   Number              (%)

(1) Relevant
securities

(2) Derivatives
(other than
options)

(3) Options and
agreements to
purchase/sell

Total


  (c)  Rights to subscribe (Note 3)

Class of relevant security:   Details



3.   DEALINGS (Note 4)

  (a)  Purchases and sales

Purchase/sale Number of Securities Price per unit
                                   (GBP)
Purchase      1,600                32.6495 CAD
Purchase      25,500               32.3800 CAD
Purchase      409                  32.5840 CAD
Purchase      8,556                32.9100 CAD
Purchase      54,320               32.6400 CAD
Purchase      12,500               32.6663 CAD
Purchase      10,600               32.3800 CAD
Purchase      4,347                32.6495 CAD
Purchase      198,300              32.6400 CAD
Purchase      11,800               32.6663 CAD
Sale          198,300              32.6400 CAD

(b)  Derivatives transactions (other than options)
Product name,  Long/Short    Number of     Price per
(e.g. CFD)     (Note 6)      Securities    unit (GBP)


(c)  Options transactions in respect of existing securities

(i)  Writing, selling, purchasing or varying

Product name,   Writing,          Number of          Exercise  Type, e.g.      Expiry   Option money
e.g. call       selling,          securities to      price     American,       date     paid/received
option          purchasing,       which the option             European etc.            per unit (GBP)
                varying etc.      relates (GBP)


(ii) Exercising

Product name, e.g.  Number of           Exercise price per
call option         securities          unit (Note 5)




(d)  Other dealings (including new securities) (Note 4)


Nature of transaction Details           Price per unit
(Note 8)                                (if applicable)
                                        (Note 5)




4.   OTHER INFORMATION
None

Agreements, arrangements or understandings relating to options or derivatives


Full details of any agreement, arrangement or understanding between the
person disclosing and any other person relating to the voting rights of
any relevant securities under any option referred to on this form or
relating to the voting rights or future acquisition or disposal of any
relevant securities to which any derivative referred to on this form is
referenced.  If none, this should be stated.




Is a Supplemental Form 8 attached? (Note 9)                 NO


Date of disclosure                         06 March 2008
Contact name                               Geoff Smith
Telephone number                           020 7116 2913
If a connected EFM, name of
offeree/offeror with which connected
If a connected EFM, state nature of
connection (Note 10)


Notes

The Notes on Form 8.3 can be viewed on the Takeover Panel's website at
www.thetakeoverpanel.org.uk