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


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934


                              TransAlta Corporation
-------------------------------------------------------------------------------
                                (Name of Issuer)


                                  Common Shares
-------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    89346D107
                               ------------------
                                 (CUSIP Number)


                                October 20, 2003
-------------------------------------------------------------------------------
             (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).




---------------------------------------------
            CUSIP No. 89346D107                                13G
---------------------------------------------

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

                      Canada Pension Plan Investment Board / Not applicable

--------------------------------------------------------------------------------
    2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                                        (a) |_|

                      Not applicable                                    (b) |_|

--------------------------------------------------------------------------------
    3. SEC USE ONLY


--------------------------------------------------------------------------------
    4. CITIZENSHIP OR PLACE OF ORGANIZATION

                      Canada
--------------------------------------------------------------------------------
     NUMBER OF SHARES          5.     SOLE VOTING POWER
  BENEFICIALLY OWNED BY
           EACH                                12,460,357
     REPORTING PERSON
           WITH
--------------------------------------------------------------------------------
                               6. SHARED VOTING POWER

                                               0
--------------------------------------------------------------------------------
                               7. SOLE DISPOSITIVE POWER

                                               12,460,357
--------------------------------------------------------------------------------
                               8. SHARED DISPOSITIVE POWER

                                               0
--------------------------------------------------------------------------------
    9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                      12,460,357
--------------------------------------------------------------------------------
    10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
                                                                      SHARES
                                                                         |_|
             (SEE INSTRUCTIONS)


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



--------------------------------------------------------------------------------
    11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                      6.53%
--------------------------------------------------------------------------------
    12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

                      CO
--------------------------------------------------------------------------------

Item 1(a).        Name of Issuer

                      The name of the issuer is TransAlta Corporation (the
"Company").


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

                      The principal executive offices of the Company are located
at 110 12th Avenue S.W., Box 1900, Station M, Calgary, Alberta T2P 2M1, Canada.


Item 2(a).        Name of Person Filing

                      This statement is being filed by Canada Pension Plan
Investment Board ("CPP Investment Board").


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

                      The address of the principal business office of the
reporting person is One Queen Street East, Suite 2700, Toronto, Ontario M5C 2W5,
Canada.


Item 2(c).        Citizenship

                      Canada.


Item 2(d).        Title of Class of Securities

                      The securities to which this statement relates are Common
Shares (the "Shares") of the Company.


Item 2(e).        CUSIP Number

                      The CUSIP number of the Shares is 89346D107.


Item 3.           If this statement is filed pursuant toss.ss.240.13d-1(b) or
                  240.13d-2(b) or (c), check whether the person filing is a:

                      Not applicable.




Item 4.           Ownership

                          (a) As of March 15, 2004, CPP Investment Board
                  directly owned 12,460,357 Shares.

                          (b) The Shares directly owned by CPP Investment Board
                  represented approximately 6.53% of the issued and outstanding
                  Shares as of March 15, 2004.

                          (c) As of March 15, 2004, CPP Investment Board had the
                  sole power to vote or to direct the voting of the Shares and
                  had the sole power to dispose of or to direct the disposition
                  of the Shares.

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

                     Not applicable.


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

                     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
                  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.
As of March 15, 2004


                                    Canada Pension Plan Investment Board


                                    By: /s/ J. H. Butler
                                        -------------------------------------
                                    Name:    J. H. Butler
                                    Title:   Vice President - General Counsel
                                             and Corporate Secretary