UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


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                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                    PURSUANT TO RULE 13a-16 OR 15d-16 UNDER
                      THE SECURITIES EXCHANGE ACT OF 1934

                           For the month of January 2006

                                  PEARSON plc
             (Exact name of registrant as specified in its charter)

                                      N/A

                (Translation of registrant's name into English)

                                   80 Strand
                            London, England WC2R 0RL
                                44-20-7010-2000
                    (Address of principal executive office)

Indicate by check mark whether the Registrant  files or will file annual reports
under cover of Form 20-F or Form 40-F:

 
    
 
      Form 20-F X                                      Form 40-F

Indicate by check mark whether the  Registrant  by  furnishing  the  information
contained  in this  Form is  also  thereby  furnishing  the  information  to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934


       Yes                                              No X

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        This Report includes the following documents: 

1. A press release from Pearson plc announcing 'Purchase of IDC Shares'



09 January 2006


Pearson: purchase of IDC shares


Pearson announces that it has purchased 1,130,739 shares in Interactive Data
Corporation (NYSE:IDC), its majority-owned, publicly-quoted financial
information company.

Pearson purchased the shares from Alan Tessler, an Interactive Data director,
and related parties at a price of $21.67 per share in cash. The purchase brings
Pearson's total holding in IDC to almost 62%.

Ends

For more information:

Luke Swanson/Deborah Lincoln        +44 (0)207 010 2310


About Interactive Data Corporation

Interactive Data Corporation is a leading global provider of securities pricing,
financial information, and analytic tools to institutional and individual
investors. The Company supplies time-sensitive pricing (including evaluated
pricing), dividend, corporate action, and descriptive information for more than
3.5 million securities traded around the world, including hard-to-value
instruments. Many of the world's best-known financial services and software
companies subscribe to the Company's services in support of their trading,
analysis, portfolio management, and valuation activities.



                                    SIGNATURE


Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.

                                   PEARSON plc

Date: 09 January 2006
  
                             By:   /s/ STEPHEN JONES
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                                   Stephen Jones
                                   Deputy Secretary