Rule 8.3 - London Stock Exchange PLC

Kinetics Asset Management
                  DISCLOSURE FORM 8.3

    DEALINGS BY PERSONS WITH INTERESTS IN SECURITIES REPRESENTING 1% OR MORE

                         (Rule 8.3 of the Takeover Code)

1. KEY INFORMATION

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Name of person dealing (Note 1)           Kinetics Asset Management, Inc.
                                          Horizon Asset Management, Inc.
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Company dealt in                          London Stock Exchange Group PLC
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Class of relevant security to which the   Ordinary Shares
 dealings being disclosed relate (Note 2)
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Date of dealing                           08 December 2006
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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)

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                                          Long                          Short
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                                          Number (%)                    Number (%)
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(1) Relevant securities                   13,715,890 6.432%             0
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(2) Derivatives (other than options)      0                             0
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(3) Options and agreements to
 purchase/sell                            0                             0
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Total                                     13,715,890 6.432%             0
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(b) Interests and short positions in relevant securities of the company, other
than the class dealt in (Note 3)

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   Class of relevant security: Class B    Long                          Short
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                                          Number (%)                    Number (%)
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(1) Relevant securities                   91,880 1.1%                   0
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(2) Derivatives (other than options)      0                             0
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(3) Options and agreements to
 purchase/sell                            0                             0
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Total                                     91,880 1.1%                   0
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(c) Rights to subscribe (Note 3)

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Class of relevant security:               Details
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3. DEALINGS (Note 4)

(a) Purchases and sales

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Purchase/sale                      Number of securities              Price per unit (Note 5)
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Purchase                           12,000                            13.14 GBP
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(b) Derivatives transactions (other than options)

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Product name,       Long/short (Note 6)    Number of securities (Note 7)   Price per unit (Note 5)
e.g. CFD
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(c) Options transactions in respect of existing securities

(i) Writing, selling, purchasing or varying

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Product name,      Writing,        Number of          Exercise  Type, e.g.   Expiry    Option money
e.g. call option    selling,        securities to     price      American,   date      paid/received
                    purchasing,     which the option             European               per unit (Note
                    varying etc.    relates (Note 7)             etc.                   5)
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(ii) Exercising

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Product name, e.g. call option     Number of securities              Exercise price per unit (Note 5)
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(d) Other dealings (including new securities) (Note 4)

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Nature of transaction (Note 8)     Details                           Price per unit (if applicable) (Note
                                                                      5)
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4. OTHER INFORMATION

Agreements, arrangements or understandings relating to options or derivatives

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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.
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Horizon Asset Management and Kinetics have a contractual relationship; whereby, Kinetics is purchasing
 research services from Horizon Asset Management. Horizon Asset Management and Kinetics are separate and
 independent companies, with different shareholders and directors, for the most part. However, since
 Horizon Asset Management and Kinetics derive investment research from a common source, i.e., the Horizon
 Research Group, a division of Horizon Asset Management, Inc. and because of certain shared personnel and
 office space, the Panel Executive has deemed Horizon Asset Management and Kinetics Asset Management to
 be a single person for the purposes of Rule 8.3 (b) of the City Code on Takeovers and Mergers. For US
 regulatory purposes, Horizon Asset Management and Kinetics are two separate and distinct companies.

A total amount of 2,407 shares of London Stock Exchange PLC are no longer under the voting control of
 Kinetics/Horizon Asset Management due to a journal transfer. Amount is reflected in the total amount of
 shares reported.
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Is a Supplemental Form 8 attached? (Note 9) YES/NO

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Date of disclosure                                          11/12/06
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Contact name                                                Andrew Fishman
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Telephone number                                            [phone]
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If a connected EFM, name of offeree/offeror with which
 connected
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If a connected EFM, state nature of connection (Note 10)
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Notes

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