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



                                  SCHEDULE 13G

                   UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 4)*


                              Carnival Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)

        Common Stock, par value $0.01 per Share of Carnival Corporation
                      Special Voting Share of Carnival plc
           Trust Shares, representing beneficial interest in the P&O
                          Princess Special Voting Trust
--------------------------------------------------------------------------------
                        (Title of Class of Securities)

                    Common Stock 143658-10-2 and 143658-30-0
                        Special Voting Share: G7214F-12-2
                            Trust Shares: 143658-30-0
            --------------------------------------------------------
                                (CUSIP Number)

                               December 31, 2007
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

   / /       Rule 13d-1(b)
   /X/       Rule 13d-1(c)
   / /       Rule 13d-1(d)


*  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 page.

   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).


                                      Page 1
                                    of 7 Pages



                                     SCHEDULE 13G

CUSIP NO. Common Stock: 143658-10-2 and 143658-30-0           Page 2 of 7 Pages
          Special Voting Share G7214F-12-2
          Trust Shares: 143658-30-0

-------------------------------------------------------------------------------
 (1) NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

  Citigroup Institutional Trust Company
-------------------------------------------------------------------------------
 (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

                                                                       (a)  / /
                                                                       (b)  / /
-------------------------------------------------------------------------------
 (3) SEC USE ONLY



-------------------------------------------------------------------------------
 (4) CITIZENSHIP OR PLACE OF ORGANIZATION                              Delaware


-------------------------------------------------------------------------------
       NUMBER OF           (5) SOLE VOTING POWER                              0

        SHARES
                           ----------------------------------------------------
     BENEFICIALLY          (6) SHARED VOTING POWER                            0

       OWNED BY
                           ----------------------------------------------------
        EACH               (7) SOLE DISPOSITIVE POWER                         0

      REPORTING
                           ----------------------------------------------------
       PERSON              (8) SHARED DISPOSITIVE POWER              61,787,525

        WITH:
-------------------------------------------------------------------------------
(9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON     61,787,525


-------------------------------------------------------------------------------
(10) CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
     INSTRUCTIONS)  / /


-------------------------------------------------------------------------------
(11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                     9.9%


-------------------------------------------------------------------------------
(12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                             00



-------------------------------------------------------------------------------



                                     SCHEDULE 13G

CUSIP NO. Common Stock: 143658-10-2 and 143658-30-0           Page 3 of 7 Pages
          Special Voting Share G7214F-12-2
          Trust Shares: 143658-30-0

-------------------------------------------------------------------------------
 (1) NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)


     Citigroup Inc.
-------------------------------------------------------------------------------
 (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

                                                                       (a)  / /
                                                                       (b)  / /
-------------------------------------------------------------------------------
 (3) SEC USE ONLY



-------------------------------------------------------------------------------
 (4) CITIZENSHIP OR PLACE OF ORGANIZATION                              Delaware


-------------------------------------------------------------------------------
       NUMBER OF           (5) SOLE VOTING POWER                              0

        SHARES
                           ----------------------------------------------------
     BENEFICIALLY          (6) SHARED VOTING POWER                   63,282,038*
                                                                             **
       OWNED BY
                           ----------------------------------------------------
        EACH               (7) SOLE DISPOSITIVE POWER                         0

      REPORTING
                           ----------------------------------------------------
       PERSON              (8) SHARED DISPOSITIVE POWER             63,282,038*
                                                                             **

        WITH:
-------------------------------------------------------------------------------
(9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON    63,282,038*
                                                                             **


-------------------------------------------------------------------------------
(10) CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
     INSTRUCTIONS)  / /


-------------------------------------------------------------------------------
(11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                   10.1%*
                                                                             **



-------------------------------------------------------------------------------
(12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                             HC


-------------------------------------------------------------------------------
*  Assumes conversion/exercise of certain securities held.
** Includes shares held by the other reporting person.




Item 1(a).     Name of Issuer:

               Carnival Corporation

Item 1(b).     Address of Issuer's Principal Executive Offices:

               3655 N.W. 87th Avenue
               Miami, FL 33178-2428

Item 2(a).*    Name of Person Filing:

               Citigroup Institutional Trust Company ("CI Trust")
               Citigroup Inc. ("Citigroup")

          *    In accordance with the Securities and Exchange Commission Release
               No. 34-39538 (January 12, 1998), this filing reflects securities
               beneficially owned by Citigroup, a holding company for a global
               financial services group, on behalf of itself and its
               subsidiaries, excluding the Old Lane Partners ("Old Lane")
               business. Old Lane, its executive officers and directors and its
               direct and indirect subsidiaries may beneficially own securities
               of the Company, and such securities are not reported in this
               filing. Citigroup (other than Old Lane) disclaims beneficial
               ownership of securities beneficially owned by Old Lane, and Old
               Lane disclaims beneficial ownership of the securities
               reported herein.

Item 2(b).     Address of Principal Office or, if none, Residence:

               The address of the principal office of CI Trust is:

               824 Market Street
               Wilmington, DE 19801

               The address of the principal office of Citigroup is:

               399 Park Avenue
               New York, NY 10043

Item 2(c).     Citizenship or Place of Organization:

               CI Trust and Citigroup are Delaware
               corporations.

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

               Common Stock
               Special Voting Share
               Trust Shares

Item 2(e).     CUSIP Number:

               143658-30-0
               G7214F-12-2
               143658-30-0


                                       Page 4
                                     of 7 Pages


Item 3.      If This Statement Is Filed Pursuant to Sections 240.13d-1(b) or
             240.13d-2(b) or (c), Check Whether the Person Filing Is a(n):

             (a)  [ ] Broker or dealer registered under Section 15 of the
                      Act (15 U.S.C. 78o);

             (b)  [ ] Bank as defined in Section 3(a)(6) of the Act
                      (15 U.S.C. 78c);

             (c)  [ ] Insurance company as defined in Section 3(a)(19) of
                      the Act (15 U.S.C. 78c);

             (d)  [ ] Investment company registered under Section 8 of the
                      Investment Company Act of 1940 (15 U.S.C. 80a-8);

             (e)  [ ] Investment adviser in accordance with Section
                      240.13d-1(b)(1)(ii)(E);

             (f)  [ ] Employee benefit plan or endowment fund in accordance
                      with Section 240.13d-1(b)(1)(ii)(F);

             (g)  [ ] Parent holding company or control person in accordance
                      with Section 240.13d-1(b)(1)(ii)(G): See Exhibit 2;

             (h)  [ ] Savings association as defined in Section 3(b) of the
                      Federal Deposit Insurance Act (12 U.S.C. 1813);

             (i)  [ ] Church plan that is excluded from the definition of an
                      investment company under Section 3(c)(14) of the
                      Investment Company Act of 1940 (15 U.S.C. 80a-3);

             (j)  [ ] Group, in accordance with Section 240.13d-1(b)(1)(ii)(J).


Item 4.   Ownership. (as of December 31, 2007)

          (a)  Amount beneficially owned: See item 9 of cover pages

          (b)  Percent of class: See item 11 of cover pages

          (c)  Number of shares as to which the person has:

                  (i)   Sole power to vote or to direct the vote:

                  (ii)  Shared power to vote or to direct the vote:

                  (iii) Sole power to dispose or to direct the disposition of:

                  (iv)  Shared power to dispose or to direct the disposition of:

                  See Items 5-8 of cover pages


                                       Page 5
                                     of 7 Pages


Item 5.   Ownership of Five Percent or Less of a Class.

          If this statement is being filed to report the fact that as of the
          date hereof the reporting person has ceased to be the beneficial owner
          of more than five percent of the class of securities, check the
          following [  ].

Item 6.   Ownership of More Than Five Percent on Behalf of Another Person.

          Not Applicable.

Item 7.   Identification and Classification of the Subsidiary Which Acquired
          the Security Being Reported on by the Parent Holding Company.

          Citigroup is the sole member of CI Trust.

Item 8.   Identification and Classification of Members of the Group.

          Not Applicable.

Item 9.   Notice of Dissolution of Group.

          Not Applicable.



                                       Page 6
                                     of 7 Pages



Item 10.  Certification.

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

Dated: February 14, 2008


                      CITIGROUP INSTITUTIONAL TRUST COMPANY
                      As Trustee for Eternity Four Trust



                      By: /s/ Megan McCafferty
                         --------------------------------------------
                         Name:  Megan McCafferty
                         Title: Vice President



                      CITIGROUP INC.



                      By: /s/ Riqueza V. Feaster
                         --------------------------------------------
                         Name:  Riqueza V. Feaster
                         Title: Assistant Secretary


                                 Page 7
                               of 7 Pages




                          EXHIBIT INDEX TO SCHEDULE 13G
                          -----------------------------



EXHIBIT 1
---------

Agreement between CI Trust and Citigroup as to joint filing of Schedule 13G.