=============================================================================
                                 UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549
                                 SCHEDULE 13D
                Under the Securities and Exchange Act of 1934

                             (Amendment No. 6)

                                  MSCI Inc.
               ------------------------------------------------
                               (Name of Issuer)

                        Common Stock, $0.01 par value
                ------------------------------------------------
                        (Title of Class of Securities)

                                  00724F101
                ------------------------------------------------
                               (CUSIP Number)

                           Allison Bennington, Esq.
                              ValueAct Capital
                 One Letterman Drive, Building D, Fourth Floor
                          San Francisco, CA  94129
                               (415) 362-3700
                ------------------------------------------------
                 (Name, address and telephone number of Person
                Authorized to Receive Notices and Communications)

                           Allison Bennington, Esq.
                              ValueAct Capital
                 One Letterman Drive, Building D, Fourth Floor
                          San Francisco, CA  94129
                               (415) 362-3700

                               November 30, 2015
                ------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the
following box [ ].

Note:  Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 240.13d-7 for other
parties to whom copies are to be sent.

*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
disclosures provided in a prior cover page.

This information required on 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).
=============================================================================


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 2 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Capital Master Fund, L.P.
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS (See Instructions)*

   WC*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   British Virgin Islands
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

   6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    PN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 3 of 13
----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   VA Partners I, LLC
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    00 (LLC)
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 4 of 13
----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Capital Management, L.P.
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    PN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 5 of 13
----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Capital Management, LLC
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    00 (LLC)
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 6 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Holdings, L.P.
---------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

---------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    PN
-----------------------------------------------------------------------------
*See Item 3
**See Items 2 and 5


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 7 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Holdings GP, LLC
---------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                        [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                   7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES          8.  SHARED VOTING POWER
   BENEFICIALLY        6,327,311**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH     9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        6,327,311**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    6,327,311**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    6.2%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    00 (LLC)
-----------------------------------------------------------------------------
*See Item 3
**See Items 2 and 5





--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 8 of 13
-----------------------------------------------------------------------------
THE PURPOSE OF THIS AMENDMENT NO. 6 TO SCHEDULE 13D IS TO AMEND THE OWNERSHIP
REPORTS OF THE REPORTING PERSONS AND TO AMEND ITEM 4(PURPOSE OF TRANSACTION),
AND ITEM 5 (INTEREST IN SECURITIES OF THE ISSUER). THE INFORMATION BELOW
SUPPLEMENTS THE INFORMATION PREVIOUSLY PROVIDED.


Item 1.     Security and Issuer

       This Schedule 13D relates to the Common Stock, $0.01 par value per
share (the "Common Stock") of MSCI Inc., a Delaware corporation (the
"Issuer").  The address of the principal executive offices  of the Issuer is
7 World Trade Center, 250 Greenwich Street, 49th Floor, New York, New York,
10007.

Item 2.     Identity and Background

       This statement is filed jointly by (a) ValueAct Capital Master Fund,
L.P. ("ValueAct Master Fund"), (b) VA Partners I, LLC ("VA Partners I"), (c)
ValueAct Capital Management, L.P. ("ValueAct Management L.P."), (d) ValueAct
Capital Management, LLC ("ValueAct Management LLC"), (e) ValueAct Holdings,
L.P. ("ValueAct Holdings") and (f) ValueAct Holdings GP, LLC ("ValueAct
Holdings GP")(collectively, the "Reporting Persons").

       ValueAct Master Fund is a limited partnership organized under the laws
of the British Virgin Islands. It has a principal business address of One
Letterman Drive, Building D, Fourth Floor, San Francisco, CA 94129.

        VA Partners I is a Delaware limited liability company, the principal
business of which is to serve as the General Partner to ValueAct Master Fund.
It has a principal business address of One Letterman Drive, Building D,
Fourth Floor, San Francisco, CA 94129.

        ValueAct Management L.P. is a Delaware limited partnership which
renders management services to ValueAct Master Fund. ValueAct Management LLC
is a Delaware limited liability company, the principal business of which is
to serve as the General Partner to ValueAct Management L.P. Each has a
principal business address of One Letterman Drive, Building D, Fourth Floor,
San Francisco, CA 94129.

       ValueAct Holdings is a Delaware limited partnership and is the sole
owner of  the limited partnership interests of ValueAct Management L.P. and
the membership interests of ValueAct Management LLC and is the majority owner
of the membership interests of VA Partners I. ValueAct Holdings GP is a
Delaware limited liability company, the principal business of which is to
serve as the General Partner to ValueAct Holdings.  Each has a principal
business address of One Letterman Drive, Building D, Fourth Floor, San
Francisco, CA 94129.

       (d) and (e). None of the entities or persons identified in this Item 2
has during the past five years been convicted of any criminal proceeding
(excluding traffic violations or similar misdemeanors), nor been a party to a
civil proceeding of a judicial or administrative body of competent judgment,
decree or final order enjoining future violations of, or prohibiting or
mandating activities subject to, federal or state securities laws or finding
any violation with respect to such laws.


--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 9 of 13
-----------------------------------------------------------------------------

Item 3.     Source and Amount of Funds or Other Consideration

	Not applicable.

Item 4.     Purpose of Transaction

      The Reporting Persons have sold the securities of the Issuer reported
in Item 5 herein as part of their standard ongoing process of portfolio
management. D. Robert Hale, a partner of ValueAct Holdings and ValueAct
Holdings GP, will continue to serve on the board of directors of the Issuer
and currently intends to stand for reelection at the Issuer's 2016 annual
meeting.

      Subject to the terms of the Cooperation Agreement by and among the
Reporting Persons and the Issuer dated January 29, 2015, the Reporting
Persons intend to have conversations with members of the Issuer's management
and board of directors to discuss ways to enhance shareholder value. The
topics of these conversations will cover a range of issues, including those
relating to the business of the Issuer, management, board composition,
operations, capital allocation, asset allocation, capitalization, dividend
policy, financial condition, mergers and acquisitions strategy, overall
business strategy, executive compensation, and corporate governance. The
Reporting Persons may also have similar conversations with other stockholders
of the Issuer and other interested parties, such as industry analysts,
existing or potential strategic partners or competitors, investment
professionals, and other investors. The Reporting Persons may at any time
reconsider and change their intentions relating to the foregoing.

      The Reporting Persons may also take one or more of the actions
described in subsections (a) through (j) of Item 4 of Schedule 13D and may
discuss such actions with the Issuer's management and the board of directors,
other stockholders of the Issuer, and other interested parties, such as those
set out above.

      The Reporting Persons intend to review their investments in the Issuer
on a continuing basis. Depending on various factors, including, without
limitation, the Issuer's financial position and strategic direction, the
outcome of the discussions and actions referenced above, actions taken by the
Issuer's board of directors, price levels of the Common Stock, other
investment opportunities available to the Reporting Persons, conditions in
the securities market and general economic and industry conditions, the
Reporting Persons may in the future take actions with respect to its
investment  position in the Issuer as it deems appropriate, including,
without limitation, purchasing additional Common Stock or selling some or all
of its Common Stock, and/or engaging in hedging or similar transactions with
respect to the Common Stock.

Item 5.    Interest in Securities of the Issuer

       (a) and (b).  Set forth below is the beneficial ownership of shares of
Common Stock of the Issuer for each person named in Item 2.  Shares reported
as beneficially owned by ValueAct Master Fund are also reported as
beneficially owned by (i) ValueAct Management L.P. as the manager of each
such investment partnership, (ii) ValueAct Management LLC, as General Partner
of ValueAct Management L.P., (iii) ValueAct Holdings, as the sole owner of

--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 10 of 13
-----------------------------------------------------------------------------

the limited partnership interests of ValueAct Management L.P. and the
membership interests of ValueAct Management LLC and as the majority owner of
the membership interests of VA Partners I and (iv) ValueAct Holdings GP, as
General Partner of ValueAct Holdings.  Shares reported as beneficially owned
by ValueAct Master Fund are also reported as beneficially owned by VA
Partners I, as General Partner of ValueAct Master Fund.  VA Partners I,
ValueAct Management L.P., ValueAct Management LLC, ValueAct Holdings and
ValueAct Holdings GP also, directly or indirectly, may own interests in one
or more than one of the partnerships from time to time.  Unless otherwise
indicated below, by reason of such relationship ValueAct Master Fund is
reported as having shared power to vote or to direct the vote, and shared
power to dispose or direct the disposition of, such shares of Common Stock,
with VA Partners I (only with respect to ValueAct Master Fund), ValueAct
Management L.P., ValueAct Management LLC, ValueAct Holdings and ValueAct
Holdings GP.

         As of the date hereof, ValueAct Master Fund is the beneficial owner
of 6,327,311 shares of Common Stock, representing approximately 6.2% of the
Issuer's outstanding Common Stock (which shares may also be deemed to be
beneficially owned by VA Partners I).

        ValueAct Management L.P., ValueAct Management LLC, ValueAct Holdings
and ValueAct Holdings GP may each be deemed the beneficial owner of an
aggregate of 6,327,311 shares of Common Stock, representing approximately
6.2% of the Issuer's outstanding Common Stock.

       All percentages set forth in this Schedule 13D are based upon the
Issuer's reported 102,675,766 outstanding shares of Common Stock as
reported in the Issuer's Form 10-Q for the quarterly period ended September
30, 2015.

       (c) Since the date of the previous filing, the Reporting Persons sold
the following shares of Common Stock in the open market:

Reporting Person          Trade Date           Shares            Price/Share
----------------          ----------          ---------          -----------
ValueAct Master Fund      11/18/2015           500,000             $69.25
                          11/30/2015           525,000             $69.90
                          12/01/2015           125,000             $70.33

       (d) and (e)  Not applicable.


Item 6.     Contracts, Arrangements, Understandings or Relationships with
            Respect to Securities of the Issuer

       Other than as described elsewhere in this Report and as previously
reported, the Reporting Persons have no understandings, arrangements,
relationships or contracts relating to the Issuer's Common Stock which are
required to be described hereunder.

Item 7.     Material to Be Filed as Exhibits

(1) Joint Filing Agreement.?


--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 11 of 13
-----------------------------------------------------------------------------
                                  SIGNATURE
          After reasonable inquiry and to the best of his knowledge and
belief, the undersigned certifies that the information set forth in this
statement is true, complete and correct.

                              POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below on this Schedule 13D hereby constitutes and appoints Jeffrey W. Ubben,
Bradley E. Singer, G. Mason Morfit and Allison Bennington, and each of
them, with full power to act without the other, his or its true and lawful
attorney-in-fact and agent, with full power of substitution and
resubstitution, for him or it and in his or its name, place and stead, in any
and all capacities (until revoked in writing) to sign any and all amendments
to this Schedule 13D, and to file the same, with all exhibits thereto and
other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorneys-in-fact and agents, and each of
them, full power and authority to do and perform each and every act and thing
requisite and necessary fully to all intents and purposes as he or it might
or could do in person, thereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

                              ValueAct Capital Master Fund L.P., by
                              VA Partners I, LLC, its General Partner

                              By:     /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer

                              VA Partners I, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Capital Management, L.P., by
                              ValueAct Capital Management, LLC its
                              General Partner

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Capital Management, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer




--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 12 of 13
-----------------------------------------------------------------------------
                              ValueAct Holdings, L.P., by
                              ValueAct Holdings GP, LLC, its
                              General Partner

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Holdings GP, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer






--------------------------                          -------------------------
CUSIP NO. 00724F101                                             Page 13 of 13
-----------------------------------------------------------------------------
                                 Exhibit 1

                           JOINT FILING UNDERTAKING

The undersigned parties hereby agree that the Schedule 13D filed herewith
(and any amendments thereto) relating to the Common Stock of MSCI Inc., is
being filed jointly on behalf of each of them with the Securities and
Exchange Commission pursuant to Section 13(d) of the Securities Exchange Act
of 1934, as amended.

                              ValueAct Capital Master Fund L.P., by
                              VA Partners I, LLC, its General Partner

                              By:     /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer

                              VA Partners I, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Capital Management, L.P., by
                              ValueAct Capital Management, LLC its
                              General Partner

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Capital Management, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer

                              ValueAct Holdings, L.P., by
                              ValueAct Holdings GP, LLC, its
                              General Partner

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer


                              ValueAct Holdings GP, LLC

                              By:    /s/  Bradley E. Singer
                                --------------------------------------
Dated:  December 3, 2015      Bradley E. Singer, Chief Operating Officer