SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13 G/A
                    Under the Securities Exchange Act of 1934




Amendment No.                           2*


Name of Issuer:                         GARTNER GROUP INC.


Title of Class of Securities:           COMMON CL B


CUSIP Number:                           366651206





*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover age.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).




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CUSIP NO.     366651206

1.       Name of Reporting Person, S.S. or I.R.S. Identification No.
         of above person:

         First Manhattan Co.             13-1957714


2.       Check the appropriate box if a member of a group:
                                         (a) [    ]
                                         (b) [ X ]

3.       SEC Use Only


4.       Citizenship or Place of Organization:
                                         New York

         NUMBER OF SHARES BENEFICIALLY OWNED
         BY EACH REPORTING PERSON WITH:

5.       Sole Voting Power:                               255,875


6.       Shared Voting Power:                           1,637,445


7.       Sole Dispositive Power:                          255,875


8.       Shared Dispositive Power:                      1,859,668


9.       Aggregate Amount Beneficially Owned by
             Each Reporting Person:                     2,115,543**


10.      Check Box If The Aggregate Amount in Row (9)
         excludes Certain Shares        [    ]

11.      Percent of Class Represented by Amount in Row 9:    6.40%

12.      Type of Reporting Person:

                      BD, IA, PN

----------------------
** Includes  442 shares owned by family members of General Partners of First
Manhattan  Co.  which are  being  reported  for  informational  purposes.  First
Manhattan  Co.  disclaims  dispositive  power  as to 221 of such  shares  and
beneficial ownership as to    221 of such shares.


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Item 1(a)    Name of Issuer:                 GARTNER GROUP INC.

Item 1(b)    Address of Issuer's
             Principal Executive Offices:    56 TOP GALLANT ROAD
                                             P.O. BOX 10212
                                             STAMFORD, CT  06904-2212

Item 2(a)    Name of Person Filing:          First Manhattan Co.

Item 2(b)    Address Principal Business Office:
                                             437 Madison Avenue
                                             New York, NY 10022

Item 2(c)    Citizenship:                    U.S.A.

Item 2(d)    Title of Class of Securities:   COMMON

Item 2(e)    CUSIP Number:                   366651206

Item 3       Check whether the person filing is a:

Item 3(a) [X] Broker or Dealer registered under Section 15 of the Act.

Item 3(b) - (d)       Not applicable.

Item 3(e) [X] Investment  Advisor  registered under Section 203
                      of the Investment Advisors Act of 1940.

Item 3(f) - (h)       Not applicable.

Item 4(a)    Amount Beneficially Owned:                    2,115,543**

Item 4(b)    Percent of Class:                                  6.40%

Item 4(c) Number of shares as to which such person has:

(i) sole power to vote or to direct the vote                  255,875

(ii) shared power to vote or to direct the vte              1,637,445

(iii) sole power to dispose or to direct the
             disposition of                                   255,875

(iv) shared power to dispose or to direct the
             disposition of                                 1,859,668

Item 5   Ownership of Five Percent or Less of Class:     [    ]


Item 6   Ownership of More than Five Percent
             on Behalf of Another Person:           Not applicable.


** Includes    442  shares owned by family members of General Partners of First
Manhattan  Co.  which are  being  reported  for  informational  purposes.  First
Manhattan  Co.  disclaims  dispositive  power  as to 221 of such  shares  and
beneficial ownership as to    221 of such shares.

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Item 7   Identification and Classification of the Subsidiary
         Which Acquired the Security Being Reported on
                By the Parent Holding Company        Not applicable.


Item 8   Identification and Classification of Members
         Of the Group                                Not applicable.


Item 9   Notice of Dissolution of Group              Not applicable.


Item 10  Certification.


By signing below I certify  that,  to the best of my knowledge  and belief,  the
securities  referred to above were  acquired in the ordinary  course of business
and were not  acquired for the purpose of and do not have the effect of changing
or  influencing  the  control  of the  issuer  of such  securities  and were not
acquired in connection with or as a participant in any  transaction  having such
purpose or effect.


Signature:

After  reasonable  inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.



February 14, 2002
----------------------------------------------
Date



-----------------------------------------------
Signature


Neal K. Stearns, General Partner
------------------------------------------------
Name/Title



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