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                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                   ----------

                                    FORM 8-A/A

               FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                     PURSUANT TO SECTION 12(b) OR 12(g) OF
                      THE SECURITIES EXCHANGE ACT OF 1934


                      OneSource Information Services, Inc.
                      ------------------------------------
             (Exact name of registrant as specified in its charter)


       Delaware                                               04-3204522       
       --------                                               ----------        
(State of incorporation                                      (IRS Employer      
     or organization)                                     Identification No.)
                                                                                
                                                             

                  150 CambridgePark Drive, Cambridge, MA 02140
                  --------------------------------------------
              (Address of principal executive offices) (Zip Code)



If this form relates to the                If this form relates to the          
registration of a class of securities      registration of a class of securities
pursuant to Section 12(b) of the           pursuant to Section 12 (g) of the    
Exchange Act and is effective              Exchange Act and is effective        
pursuant to General Instruction            pursuant to General Instruction      
A.(c), please check the following          A.(d), please check the following    
box:   [ ]                                 box:   [X]         
                                           


Securities Act registration statement file number to which this form relates:
333-73262
(If applicable)


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       Securities to be registered pursuant to Section 12(b) of the Act:

   Title of each class                     Name of each exchange on which 
   to be so registered                     each class is to be registered 
   -------------------                     ------------------------------ 
         None                                        Not Applicable


       Securities to be registered pursuant to Section 12(g) of the Act:


                          Common Stock, $.01 par value
                                      ----
                                (Title of Class)


Item 1. Description of Registrant's Securities to be Registered
        -------------------------------------------------------

     Information concerning the Registrant's Common Stock is contained in the
Registrant's Form S-1 Registration Statement, filed with the Securities and
Exchange Commission on March 3, 1999, as amended pursuant to the Securities Act
of 1933, as amended (the "S-1 Registration Statement"), and such information is
incorporated herein by reference.

Item 2. Exhibits
        --------

Exhibit No.                            Exhibit
- -----------                            -------

1.                  Form of Restated Certificate of Incorporation of the
                    Registrant, to be filed upon closing of the offering
                    (Incorporated by reference to Exhibit 3.01 to the S-1
                    Registration Statement.).

2.                  Amended and Restated Certificate of Incorporation of the
                    Registrant (Incorporated by reference to Exhibit 3.02 to the
                    S-1 Registration Statement.).

3.                  By-Laws, as amended and restated, of the of the Registrant
                    (Incorporated by reference to Exhibit 3.03 to the S-1
                    Registration Statement.).

4.                  Form of Second Amended and Restated By-Laws of the
                    Registrant, to be adopted upon closing of the offering
                    (Incorporated by reference to Exhibit 3.04 to the S-1
                    Registration Statement.).

5.                  Specimen certificate representing the common stock
                    (Incorporated by reference to Exhibit 4.01 to the S-1
                    Registration Statement.).

6.                  Registration Agreement among the Registrant and certain
                    shareholders dated September 8, 1993 (Incorporated by
                    reference to Exhibit 10.04 to the S-1 Registration
                    Statement.).


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                                   SIGNATURE
                                   ---------

     Pursuant to the requirements of Section 12 of the Securities Exchange Act
of 1934, the Registrant has duly caused this registration statement to be signed
on its behalf by the undersigned, thereto duly authorized.

          
                                   OneSource Information Services, Inc.



                                   By: /s/ Roy D. Landon                      
                                      ----------------------------------------
                                      Roy D. Landon                           
                                      Vice President, Finance & Administration
                                                                              
                                   

Date: April 28, 1999